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href="glib-Date-and-Time-Functions.html#id3149705" title="Description"><link rel="section" href="glib-Date-and-Time-Functions.html#id3149961" title="Details"><meta name="generator" content="GTK-Doc V1.2 (XML mode)"><link rel="stylesheet" href="style.css" type="text/css"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table class="navigation" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"><td><a accesskey="p" href="glib-I18N.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td><td><a accesskey="u" href="glib-utilities.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td><td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td><th width="100%" align="center">GLib Reference Manual</th><td><a accesskey="n" href="glib-Random-Numbers.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td></tr></table><div class="refentry" lang="en"><a name="glib-Date-and-Time-Functions"></a><div class="titlepage"><div></div><div></div></div><div class="refnamediv"><h2><span class="refentrytitle">Date and Time Functions</span></h2><p>Date and Time Functions — calendrical calculations and miscellaneous time stuff.</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
#include <glib.h>
#define <a href="glib-Date-and-Time-Functions.html#G-USEC-PER-SEC-CAPS">G_USEC_PER_SEC</a>
struct <a href="glib-Date-and-Time-Functions.html#GTimeVal">GTimeVal</a>;
void <a href="glib-Date-and-Time-Functions.html#g-get-current-time">g_get_current_time</a> (<a href="glib-Date-and-Time-Functions.html#GTimeVal">GTimeVal</a> *result);
void <a href="glib-Date-and-Time-Functions.html#g-usleep">g_usleep</a> (<a href="glib-Basic-Types.html#gulong">gulong</a> microseconds);
void <a href="glib-Date-and-Time-Functions.html#g-time-val-add">g_time_val_add</a> (<a href="glib-Date-and-Time-Functions.html#GTimeVal">GTimeVal</a> *time_,
<a href="glib-Basic-Types.html#glong">glong</a> microseconds);
struct <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>;
typedef <a href="glib-Date-and-Time-Functions.html#GTime">GTime</a>;
enum <a href="glib-Date-and-Time-Functions.html#GDateDMY">GDateDMY</a>;
typedef <a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a>;
enum <a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a>;
typedef <a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a>;
enum <a href="glib-Date-and-Time-Functions.html#GDateWeekday">GDateWeekday</a>;
#define <a href="glib-Date-and-Time-Functions.html#G-DATE-BAD-DAY-CAPS">G_DATE_BAD_DAY</a>
#define <a href="glib-Date-and-Time-Functions.html#G-DATE-BAD-JULIAN-CAPS">G_DATE_BAD_JULIAN</a>
#define <a href="glib-Date-and-Time-Functions.html#G-DATE-BAD-YEAR-CAPS">G_DATE_BAD_YEAR</a>
<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* <a href="glib-Date-and-Time-Functions.html#g-date-new">g_date_new</a> (void);
<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* <a href="glib-Date-and-Time-Functions.html#g-date-new-dmy">g_date_new_dmy</a> (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* <a href="glib-Date-and-Time-Functions.html#g-date-new-julian">g_date_new_julian</a> (<a href="glib-Basic-Types.html#guint32">guint32</a> julian_day);
void <a href="glib-Date-and-Time-Functions.html#g-date-clear">g_date_clear</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_dates);
void <a href="glib-Date-and-Time-Functions.html#g-date-free">g_date_free</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-day">g_date_set_day</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-month">g_date_set_month</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-year">g_date_set_year</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-dmy">g_date_set_dmy</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> y);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-julian">g_date_set_julian</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint32">guint32</a> julian_date);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-time">g_date_set_time</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GTime">GTime</a> time_);
void <a href="glib-Date-and-Time-Functions.html#g-date-set-parse">g_date_set_parse</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
const <a href="glib-Basic-Types.html#gchar">gchar</a> *str);
void <a href="glib-Date-and-Time-Functions.html#g-date-add-days">g_date_add_days</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_days);
void <a href="glib-Date-and-Time-Functions.html#g-date-subtract-days">g_date_subtract_days</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_days);
void <a href="glib-Date-and-Time-Functions.html#g-date-add-months">g_date_add_months</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_months);
void <a href="glib-Date-and-Time-Functions.html#g-date-subtract-months">g_date_subtract_months</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_months);
void <a href="glib-Date-and-Time-Functions.html#g-date-add-years">g_date_add_years</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_years);
void <a href="glib-Date-and-Time-Functions.html#g-date-subtract-years">g_date_subtract_years</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_years);
<a href="glib-Basic-Types.html#gint">gint</a> <a href="glib-Date-and-Time-Functions.html#g-date-days-between">g_date_days_between</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date1,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date2);
<a href="glib-Basic-Types.html#gint">gint</a> <a href="glib-Date-and-Time-Functions.html#g-date-compare">g_date_compare</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *lhs,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *rhs);
void <a href="glib-Date-and-Time-Functions.html#g-date-clamp">g_date_clamp</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *min_date,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *max_date);
void <a href="glib-Date-and-Time-Functions.html#g-date-order">g_date_order</a> (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date1,
<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date2);
<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-day">g_date_get_day</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-month">g_date_get_month</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-year">g_date_get_year</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#guint32">guint32</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-julian">g_date_get_julian</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Date-and-Time-Functions.html#GDateWeekday">GDateWeekday</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-weekday">g_date_get_weekday</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#guint">guint</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-day-of-year">g_date_get_day_of_year</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#guint8">guint8</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-days-in-month">g_date_get_days_in_month</a> (<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-is-first-of-month">g_date_is_first_of_month</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-is-last-of-month">g_date_is_last_of_month</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-is-leap-year">g_date_is_leap_year</a> (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#guint">guint</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-monday-week-of-year">g_date_get_monday_week_of_year</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#guint8">guint8</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-monday-weeks-in-year">g_date_get_monday_weeks_in_year</a> (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#guint">guint</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-sunday-week-of-year">g_date_get_sunday_week_of_year</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#guint8">guint8</a> <a href="glib-Date-and-Time-Functions.html#g-date-get-sunday-weeks-in-year">g_date_get_sunday_weeks_in_year</a> (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#gsize">gsize</a> <a href="glib-Date-and-Time-Functions.html#g-date-strftime">g_date_strftime</a> (<a href="glib-Basic-Types.html#gchar">gchar</a> *s,
<a href="glib-Basic-Types.html#gsize">gsize</a> slen,
const <a href="glib-Basic-Types.html#gchar">gchar</a> *format,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
void <a href="glib-Date-and-Time-Functions.html#g-date-to-struct-tm">g_date_to_struct_tm</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
struct tm *tm);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid">g_date_valid</a> (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-day">g_date_valid_day</a> (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-month">g_date_valid_month</a> (<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-year">g_date_valid_year</a> (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-dmy">g_date_valid_dmy</a> (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-julian">g_date_valid_julian</a> (<a href="glib-Basic-Types.html#guint32">guint32</a> julian_date);
<a href="glib-Basic-Types.html#gboolean">gboolean</a> <a href="glib-Date-and-Time-Functions.html#g-date-valid-weekday">g_date_valid_weekday</a> (<a href="glib-Date-and-Time-Functions.html#GDateWeekday">GDateWeekday</a> weekday);
</pre></div><div class="refsect1" lang="en"><a name="id3149705"></a><h2>Description</h2><p>
The <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> data structure represents a day between January 1, Year 1,
and sometime a few thousand years in the future (right now it will go
to the year 65535 or so, but <a href="glib-Date-and-Time-Functions.html#g-date-set-parse"><tt class="function">g_date_set_parse()</tt></a> only parses up to the
year 8000 or so - just count on "a few thousand"). <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> is meant to
represent everyday dates, not astronomical dates or historical dates
or ISO timestamps or the like. It extrapolates the current Gregorian
calendar forward and backward in time; there is no attempt to change
the calendar to match time periods or locations. <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> does not store
time information; it represents a <span class="emphasis"><em>day</em></span>.
</p><p>
The <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> implementation has several nice features; it is only a
64-bit struct, so storing large numbers of dates is very efficient. It
can keep both a Julian and day-month-year representation of the date,
since some calculations are much easier with one representation or the
other. A Julian representation is simply a count of days since some
fixed day in the past; for <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> the fixed day is January 1, 1 AD.
("Julian" dates in the <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> API aren't really Julian dates in the
technical sense; technically, Julian dates count from the start of the
Julian period, Jan 1, 4713 BC).
</p><p>
<a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> is simple to use. First you need a "blank" date; you can get a
dynamically allocated date from <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a>, or you can declare an
automatic variable or array and initialize it to a sane state by
calling <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a>. A cleared date is sane; it's safe to call
<a href="glib-Date-and-Time-Functions.html#g-date-set-dmy"><tt class="function">g_date_set_dmy()</tt></a> and the other mutator functions to initialize the
value of a cleared date. However, a cleared date is initially
<span class="emphasis"><em>invalid</em></span>, meaning that it doesn't represent a day
that exists. It is undefined to call any of the date calculation
routines on an invalid date. If you obtain a date from a user or other
unpredictable source, you should check its validity with the
<a href="glib-Date-and-Time-Functions.html#g-date-valid"><tt class="function">g_date_valid()</tt></a> predicate. <a href="glib-Date-and-Time-Functions.html#g-date-valid"><tt class="function">g_date_valid()</tt></a> is also used to check for
errors with <a href="glib-Date-and-Time-Functions.html#g-date-set-parse"><tt class="function">g_date_set_parse()</tt></a> and other functions that can
fail. Dates can be invalidated by calling <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a> again.
</p><p>
<span class="emphasis"><em>It is very important to use the API to access the <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>
struct.</em></span> Often only the day-month-year or only the Julian
representation is valid. Sometimes neither is valid. Use the API.
</p><p>
GLib doesn't contain any time-manipulation functions; however, there
is a <a href="glib-Date-and-Time-Functions.html#GTime"><span class="type">GTime</span></a> typedef which is equivalent to <span class="type">time_t</span>, and a <a href="glib-Date-and-Time-Functions.html#GTimeVal"><span class="type">GTimeVal</span></a>
struct which represents a more precise time (with microseconds). You
can request the current time as a <a href="glib-Date-and-Time-Functions.html#GTimeVal"><span class="type">GTimeVal</span></a> with <a href="glib-Date-and-Time-Functions.html#g-get-current-time"><tt class="function">g_get_current_time()</tt></a>.
</p></div><div class="refsect1" lang="en"><a name="id3149961"></a><h2>Details</h2><div class="refsect2" lang="en"><a name="id3149967"></a><h3><a name="G-USEC-PER-SEC-CAPS"></a>G_USEC_PER_SEC</h3><a class="indexterm" name="id3149978"></a><pre class="programlisting">#define G_USEC_PER_SEC 1000000
</pre><p>
Number of microseconds in one second (1 million). This macro is provided for
code readability.
</p></div><hr><div class="refsect2" lang="en"><a name="id3149995"></a><h3><a name="GTimeVal"></a>struct GTimeVal</h3><a class="indexterm" name="id3150006"></a><pre class="programlisting">struct GTimeVal {
glong tv_sec;
glong tv_usec;
};
</pre><p>
Represents a precise time, with seconds and microseconds. Same as the
<span class="structname">struct timeval</span> returned by the
<tt class="function"><tt class="function">gettimeofday()</tt></tt> UNIX call.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><a href="glib-Basic-Types.html#glong">glong</a> <i class="structfield"><tt>tv_sec</tt></i></span></td><td>seconds.
</td></tr><tr><td><span class="term"><a href="glib-Basic-Types.html#glong">glong</a> <i class="structfield"><tt>tv_usec</tt></i></span></td><td>microseconds.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3150084"></a><h3><a name="g-get-current-time"></a>g_get_current_time ()</h3><a class="indexterm" name="id3150096"></a><pre class="programlisting">void g_get_current_time (<a href="glib-Date-and-Time-Functions.html#GTimeVal">GTimeVal</a> *result);</pre><p>
Equivalent to the UNIX <tt class="function">gettimeofday()</tt> function, but portable.</p><p>
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>result</tt></i> :</span></td><td> <a href="glib-Date-and-Time-Functions.html#GTimeVal"><span class="type">GTimeVal</span></a> structure in which to store current time.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3150165"></a><h3><a name="g-usleep"></a>g_usleep ()</h3><a class="indexterm" name="id3150175"></a><pre class="programlisting">void g_usleep (<a href="glib-Basic-Types.html#gulong">gulong</a> microseconds);</pre><p>
Pauses the current thread for the given number of microseconds. There
are 1 million microseconds per second (represented by the
<a href="glib-Date-and-Time-Functions.html#G-USEC-PER-SEC-CAPS"><span class="type">G_USEC_PER_SEC</span></a> macro). <a href="glib-Date-and-Time-Functions.html#g-usleep"><tt class="function">g_usleep()</tt></a> may have limited precision,
depending on hardware and operating system; don't rely on the exact
length of the sleep.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>microseconds</tt></i> :</span></td><td>number of microseconds to pause.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3150245"></a><h3><a name="g-time-val-add"></a>g_time_val_add ()</h3><a class="indexterm" name="id3150256"></a><pre class="programlisting">void g_time_val_add (<a href="glib-Date-and-Time-Functions.html#GTimeVal">GTimeVal</a> *time_,
<a href="glib-Basic-Types.html#glong">glong</a> microseconds);</pre><p>
Adds the given number of microseconds to <i class="parameter"><tt>time_</tt></i>. <i class="parameter"><tt>microseconds</tt></i> can
also be negative to decrease the value of <i class="parameter"><tt>time_</tt></i>.</p><p>
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>time_</tt></i> :</span></td><td> a <a href="glib-Date-and-Time-Functions.html#GTimeVal"><span class="type">GTimeVal</span></a>
</td></tr><tr><td><span class="term"><i class="parameter"><tt>microseconds</tt></i> :</span></td><td> number of microseconds to add to <i class="parameter"><tt>time</tt></i>
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3150359"></a><h3><a name="GDate"></a>struct GDate</h3><a class="indexterm" name="id3150370"></a><pre class="programlisting">struct GDate {
guint julian_days : 32; /* julian days representation - we use a
* bitfield hoping that 64 bit platforms
* will pack this whole struct in one big
* int
*/
guint julian : 1; /* julian is valid */
guint dmy : 1; /* dmy is valid */
/* DMY representation */
guint day : 6;
guint month : 4;
guint year : 16;
};
</pre><p>
Represents a day between January 1, Year 1 and a few thousand years in
the future. None of its members should be accessed directly. If the
<span class="structname">GDate</span> is obtained from <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a>, it will
be safe to mutate but invalid and thus not safe for calendrical computations.
If it's declared on the stack, it will contain garbage so must be
initialized with <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a>. <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a> makes the date invalid
but sane. An invalid date doesn't represent a day, it's "empty." A
date becomes valid after you set it to a Julian day or you set a day,
month, and year.
</p></div><hr><div class="refsect2" lang="en"><a name="id3148175"></a><h3><a name="GTime"></a>GTime</h3><a class="indexterm" name="id3148185"></a><pre class="programlisting">typedef gint32 GTime;
</pre><p>
Simply a replacement for <span class="type">time_t</span>. Unrelated to <a href="glib-Timers.html#GTimer"><span class="type">GTimer</span></a>.
</p></div><hr><div class="refsect2" lang="en"><a name="id3148214"></a><h3><a name="GDateDMY"></a>enum GDateDMY</h3><a class="indexterm" name="id3148225"></a><pre class="programlisting">typedef enum
{
G_DATE_DAY = 0,
G_DATE_MONTH = 1,
G_DATE_YEAR = 2
} GDateDMY;
</pre><p>
This enumeration isn't used in the API, but may be useful if you need
to mark a number as a day, month, or year.
</p></div><hr><div class="refsect2" lang="en"><a name="id3148243"></a><h3><a name="GDateDay"></a>GDateDay</h3><a class="indexterm" name="id3148253"></a><pre class="programlisting">typedef guint8 GDateDay; /* day of the month */
</pre><p>
Integer representing a day of the month; between 1 and
31. <a href="glib-Date-and-Time-Functions.html#G-DATE-BAD-DAY-CAPS"><span class="type">G_DATE_BAD_DAY</span></a> represents an invalid day of the month.
</p></div><hr><div class="refsect2" lang="en"><a name="id3150676"></a><h3><a name="GDateMonth"></a>enum GDateMonth</h3><a class="indexterm" name="id3150687"></a><pre class="programlisting">typedef enum
{
G_DATE_BAD_MONTH = 0,
G_DATE_JANUARY = 1,
G_DATE_FEBRUARY = 2,
G_DATE_MARCH = 3,
G_DATE_APRIL = 4,
G_DATE_MAY = 5,
G_DATE_JUNE = 6,
G_DATE_JULY = 7,
G_DATE_AUGUST = 8,
G_DATE_SEPTEMBER = 9,
G_DATE_OCTOBER = 10,
G_DATE_NOVEMBER = 11,
G_DATE_DECEMBER = 12
} GDateMonth;
</pre><p>
Enumeration representing a month; values are <span class="type">G_DATE_JANUARY</span>,
<span class="type">G_DATE_FEBRUARY</span>, etc. <span class="type">G_DATE_BAD_MONTH</span> is the invalid value.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><tt class="literal">G_DATE_BAD_MONTH</tt></span></td><td>invalid value.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_JANUARY</tt></span></td><td>January.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_FEBRUARY</tt></span></td><td>February.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_MARCH</tt></span></td><td>March.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_APRIL</tt></span></td><td>April.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_MAY</tt></span></td><td>May.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_JUNE</tt></span></td><td>June.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_JULY</tt></span></td><td>July.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_AUGUST</tt></span></td><td>August.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_SEPTEMBER</tt></span></td><td>September.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_OCTOBER</tt></span></td><td>October.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_NOVEMBER</tt></span></td><td>November.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_DECEMBER</tt></span></td><td>December.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3150933"></a><h3><a name="GDateYear"></a>GDateYear</h3><a class="indexterm" name="id3150944"></a><pre class="programlisting">typedef guint16 GDateYear;
</pre><p>
Integer representing a year; <a href="glib-Date-and-Time-Functions.html#G-DATE-BAD-YEAR-CAPS"><span class="type">G_DATE_BAD_YEAR</span></a> is the invalid
value. The year must be 1 or higher; negative (BC) years are not
allowed. The year is represented with four digits.
</p></div><hr><div class="refsect2" lang="en"><a name="id3150971"></a><h3><a name="GDateWeekday"></a>enum GDateWeekday</h3><a class="indexterm" name="id3150981"></a><pre class="programlisting">typedef enum
{
G_DATE_BAD_WEEKDAY = 0,
G_DATE_MONDAY = 1,
G_DATE_TUESDAY = 2,
G_DATE_WEDNESDAY = 3,
G_DATE_THURSDAY = 4,
G_DATE_FRIDAY = 5,
G_DATE_SATURDAY = 6,
G_DATE_SUNDAY = 7
} GDateWeekday;
</pre><p>
Enumeration representing a day of the week; <span class="type">G_DATE_MONDAY</span>,
<span class="type">G_DATE_TUESDAY</span>, etc. <span class="type">G_DATE_BAD_WEEKDAY</span> is an invalid weekday.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><tt class="literal">G_DATE_BAD_WEEKDAY</tt></span></td><td>invalid value.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_MONDAY</tt></span></td><td>Monday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_TUESDAY</tt></span></td><td>Tuesday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_WEDNESDAY</tt></span></td><td>Wednesday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_THURSDAY</tt></span></td><td>Thursday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_FRIDAY</tt></span></td><td>Friday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_SATURDAY</tt></span></td><td>Saturday.
</td></tr><tr><td><span class="term"><tt class="literal">G_DATE_SUNDAY</tt></span></td><td>Sunday.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151153"></a><h3><a name="G-DATE-BAD-DAY-CAPS"></a>G_DATE_BAD_DAY</h3><a class="indexterm" name="id3151164"></a><pre class="programlisting">#define G_DATE_BAD_DAY 0U
</pre><p>
Represents an invalid <a href="glib-Date-and-Time-Functions.html#GDateDay"><span class="type">GDateDay</span></a>.
</p></div><hr><div class="refsect2" lang="en"><a name="id3151188"></a><h3><a name="G-DATE-BAD-JULIAN-CAPS"></a>G_DATE_BAD_JULIAN</h3><a class="indexterm" name="id3151200"></a><pre class="programlisting">#define G_DATE_BAD_JULIAN 0U
</pre><p>
Represents an invalid Julian day number.
</p></div><hr><div class="refsect2" lang="en"><a name="id3151216"></a><h3><a name="G-DATE-BAD-YEAR-CAPS"></a>G_DATE_BAD_YEAR</h3><a class="indexterm" name="id3151227"></a><pre class="programlisting">#define G_DATE_BAD_YEAR 0U
</pre><p>
Represents an invalid year.
</p></div><hr><div class="refsect2" lang="en"><a name="id3151243"></a><h3><a name="g-date-new"></a>g_date_new ()</h3><a class="indexterm" name="id3151254"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* g_date_new (void);</pre><p>
Allocates a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> and initializes it to a sane state. The new date will
be cleared (as if you'd called <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a>) but invalid (it won't
represent an existing day). Free the return value with <a href="glib-Date-and-Time-Functions.html#g-date-free"><tt class="function">g_date_free()</tt></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a newly-allocated <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151329"></a><h3><a name="g-date-new-dmy"></a>g_date_new_dmy ()</h3><a class="indexterm" name="id3151340"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* g_date_new_dmy (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Like <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a>, but also sets the value of the date. Assuming the
day-month-year triplet you pass in represents an existing day, the
returned date will be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>day</tt></i> :</span></td><td>day of the month.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month of the year.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a newly-allocated <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> initialized with <i class="parameter"><tt>day</tt></i>, <i class="parameter"><tt>month</tt></i>, and <i class="parameter"><tt>year</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151478"></a><h3><a name="g-date-new-julian"></a>g_date_new_julian ()</h3><a class="indexterm" name="id3151489"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDate">GDate</a>* g_date_new_julian (<a href="glib-Basic-Types.html#guint32">guint32</a> julian_day);</pre><p>
Like <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a>, but also sets the value of the date. Assuming the
Julian day number you pass in is valid (greater than 0, less than an
unreasonably large number), the returned date will be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>julian_day</tt></i> :</span></td><td>days since January 1, Year 1.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>a newly-allocated <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> initialized with <i class="parameter"><tt>julian_day</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151574"></a><h3><a name="g-date-clear"></a>g_date_clear ()</h3><a class="indexterm" name="id3151585"></a><pre class="programlisting">void g_date_clear (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_dates);</pre><p>
Initializes one or more <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> structs to a sane but invalid
state. The cleared dates will not represent an existing date, but will
not contain garbage. Useful to init a date declared on the stack.
Validity can be tested with <a href="glib-Date-and-Time-Functions.html#g-date-valid"><tt class="function">g_date_valid()</tt></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>pointer to one or more dates to clear.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_dates</tt></i> :</span></td><td>number of dates to clear.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151675"></a><h3><a name="g-date-free"></a>g_date_free ()</h3><a class="indexterm" name="id3151686"></a><pre class="programlisting">void g_date_free (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Frees a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> returned from <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a>.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151758"></a><h3><a name="g-date-set-day"></a>g_date_set_day ()</h3><a class="indexterm" name="id3151769"></a><pre class="programlisting">void g_date_set_day (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day);</pre><p>
Sets the day of the month for a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. If the resulting day-month-year
triplet is invalid, the date will be invalid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>day</tt></i> :</span></td><td>day to set.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151854"></a><h3><a name="g-date-set-month"></a>g_date_set_month ()</h3><a class="indexterm" name="id3151865"></a><pre class="programlisting">void g_date_set_month (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month);</pre><p>
Sets the month of the year for a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. If the resulting
day-month-year triplet is invalid, the date will be invalid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month to set.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3151950"></a><h3><a name="g-date-set-year"></a>g_date_set_year ()</h3><a class="indexterm" name="id3151961"></a><pre class="programlisting">void g_date_set_year (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Sets the year for a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. If the resulting day-month-year triplet is
invalid, the date will be invalid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year to set.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152046"></a><h3><a name="g-date-set-dmy"></a>g_date_set_dmy ()</h3><a class="indexterm" name="id3152057"></a><pre class="programlisting">void g_date_set_dmy (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> y);</pre><p>
Sets the value of a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> from a day, month, and year. The day-month-year
triplet must be valid; if you aren't sure it is, call <a href="glib-Date-and-Time-Functions.html#g-date-valid-dmy"><tt class="function">g_date_valid_dmy()</tt></a> to
check before you set it.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>day</tt></i> :</span></td><td>day.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>y</tt></i> :</span></td><td>year.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152196"></a><h3><a name="g-date-set-julian"></a>g_date_set_julian ()</h3><a class="indexterm" name="id3152207"></a><pre class="programlisting">void g_date_set_julian (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint32">guint32</a> julian_date);</pre><p>
Sets the value of a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> from a Julian day number.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>julian_date</tt></i> :</span></td><td>Julian day number (days since January 1, Year 1).
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152292"></a><h3><a name="g-date-set-time"></a>g_date_set_time ()</h3><a class="indexterm" name="id3152303"></a><pre class="programlisting">void g_date_set_time (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Date-and-Time-Functions.html#GTime">GTime</a> time_);</pre><p>
Sets the value of a date from a <a href="glib-Date-and-Time-Functions.html#GTime"><span class="type">GTime</span></a> (<span class="type">time_t</span>) value.
To set the value of a date to the current day, you could write:
</p><div class="informalexample"><pre class="programlisting">
g_date_set_time (date, time (NULL));
</pre></div><p>
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>time_</tt></i> :</span></td><td><a href="glib-Date-and-Time-Functions.html#GTime"><span class="type">GTime</span></a> value to set.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152405"></a><h3><a name="g-date-set-parse"></a>g_date_set_parse ()</h3><a class="indexterm" name="id3152416"></a><pre class="programlisting">void g_date_set_parse (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
const <a href="glib-Basic-Types.html#gchar">gchar</a> *str);</pre><p>
Parses a user-inputted string <i class="parameter"><tt>str</tt></i>, and try to figure out what date it
represents, taking the current locale into account. If the string is
successfully parsed, the date will be valid after the call. Otherwise,
it will be invalid. You should check using <a href="glib-Date-and-Time-Functions.html#g-date-valid"><tt class="function">g_date_valid()</tt></a> to see
whether the parsing succeeded.
</p><p>
This function is not appropriate for file formats and the like; it
isn't very precise, and its exact behavior varies with the
locale. It's intended to be a heuristic routine that guesses what the
user means by a given string (and it does work pretty well in that
capacity).
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to fill in.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>str</tt></i> :</span></td><td>string to parse.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152521"></a><h3><a name="g-date-add-days"></a>g_date_add_days ()</h3><a class="indexterm" name="id3152532"></a><pre class="programlisting">void g_date_add_days (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_days);</pre><p>
Increments a date some number of days. To move forward by weeks, add
weeks*7 days. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to increment.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_days</tt></i> :</span></td><td>number of days to move the date forward.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152610"></a><h3><a name="g-date-subtract-days"></a>g_date_subtract_days ()</h3><a class="indexterm" name="id3152622"></a><pre class="programlisting">void g_date_subtract_days (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_days);</pre><p>
Moves a date some number of days into the past. To move by weeks, just
move by weeks*7 days. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to decrement.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_days</tt></i> :</span></td><td>number of days to move.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152700"></a><h3><a name="g-date-add-months"></a>g_date_add_months ()</h3><a class="indexterm" name="id3152711"></a><pre class="programlisting">void g_date_add_months (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_months);</pre><p>
Increments a date by some number of months. If the day of the month is
greater than 28, this routine may change the day of the month (because
the destination month may not have the current day in it). The date
must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to increment.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_months</tt></i> :</span></td><td>number of months to move forward.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152790"></a><h3><a name="g-date-subtract-months"></a>g_date_subtract_months ()</h3><a class="indexterm" name="id3152802"></a><pre class="programlisting">void g_date_subtract_months (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_months);</pre><p>
Moves a date some number of months into the past. If the current day of
the month doesn't exist in the destination month, the day of the month
may change. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to decrement.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_months</tt></i> :</span></td><td>number of months to move.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152881"></a><h3><a name="g-date-add-years"></a>g_date_add_years ()</h3><a class="indexterm" name="id3152892"></a><pre class="programlisting">void g_date_add_years (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_years);</pre><p>
Increments a date by some number of years. If the date is February 29,
and the destination year is not a leap year, the date will be changed
to February 28. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to increment.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_years</tt></i> :</span></td><td>number of years to move forward.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3152971"></a><h3><a name="g-date-subtract-years"></a>g_date_subtract_years ()</h3><a class="indexterm" name="id3152983"></a><pre class="programlisting">void g_date_subtract_years (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
<a href="glib-Basic-Types.html#guint">guint</a> n_years);</pre><p>
Moves a date some number of years into the past. If the current day
doesn't exist in the destination year (i.e. it's February 29 and you
move to a non-leap-year) then the day is changed to February 29. The date
must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to decrement.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>n_years</tt></i> :</span></td><td>number of years to move.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153062"></a><h3><a name="g-date-days-between"></a>g_date_days_between ()</h3><a class="indexterm" name="id3153074"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gint">gint</a> g_date_days_between (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date1,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date2);</pre><p>
Computes the number of days between two dates.
If <i class="parameter"><tt>date2</tt></i> is prior to <i class="parameter"><tt>date1</tt></i>, the returned value is negative.
Both dates must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date1</tt></i> :</span></td><td>the first date.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>date2</tt></i> :</span></td><td>the second date.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>the number of days between <i class="parameter"><tt>date1</tt></i> and <i class="parameter"><tt>date2</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153178"></a><h3><a name="g-date-compare"></a>g_date_compare ()</h3><a class="indexterm" name="id3153189"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gint">gint</a> g_date_compare (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *lhs,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *rhs);</pre><p>
<tt class="function"><tt class="function">qsort()</tt></tt>-style comparsion function for dates. Both
dates must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>lhs</tt></i> :</span></td><td>first date to compare.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>rhs</tt></i> :</span></td><td>second date to compare.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>0 for equal, less than zero if <i class="parameter"><tt>lhs</tt></i> is less than <i class="parameter"><tt>rhs</tt></i>,
greater than zero if <i class="parameter"><tt>lhs</tt></i> is greater than <i class="parameter"><tt>rhs</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153308"></a><h3><a name="g-date-clamp"></a>g_date_clamp ()</h3><a class="indexterm" name="id3153319"></a><pre class="programlisting">void g_date_clamp (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *min_date,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *max_date);</pre><p>
If <i class="parameter"><tt>date</tt></i> is prior to <i class="parameter"><tt>min_date</tt></i>, sets <i class="parameter"><tt>date</tt></i> equal to <i class="parameter"><tt>min_date</tt></i>.
If <i class="parameter"><tt>date</tt></i> falls after <i class="parameter"><tt>max_date</tt></i>, sets <i class="parameter"><tt>date</tt></i> equal to <i class="parameter"><tt>max_date</tt></i>.
Either <i class="parameter"><tt>min_date</tt></i> and <i class="parameter"><tt>max_date</tt></i> may be <tt class="literal">NULL</tt>. All non-<tt class="literal">NULL</tt> dates
must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to clamp.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>min_date</tt></i> :</span></td><td>minimum accepted value for <i class="parameter"><tt>date</tt></i>.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>max_date</tt></i> :</span></td><td>maximum accepted value for <i class="parameter"><tt>date</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153501"></a><h3><a name="g-date-order"></a>g_date_order ()</h3><a class="indexterm" name="id3153512"></a><pre class="programlisting">void g_date_order (<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date1,
<a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date2);</pre><p>
Checks if <i class="parameter"><tt>date1</tt></i> is less than or equal to <i class="parameter"><tt>date2</tt></i>,
and swap the values if this is not the case.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date1</tt></i> :</span></td><td>the first date.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>date2</tt></i> :</span></td><td>the second date.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153593"></a><h3><a name="g-date-get-day"></a>g_date_get_day ()</h3><a class="indexterm" name="id3153603"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> g_date_get_day (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the day of the month. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to extract the day of the month from.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>day of the month.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153669"></a><h3><a name="g-date-get-month"></a>g_date_get_month ()</h3><a class="indexterm" name="id3153680"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> g_date_get_month (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the month of the year. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to get the month from.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>month of the year as a <a href="glib-Date-and-Time-Functions.html#GDateMonth"><span class="type">GDateMonth</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153753"></a><h3><a name="g-date-get-year"></a>g_date_get_year ()</h3><a class="indexterm" name="id3153764"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> g_date_get_year (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the year of a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>year in which the date falls.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153837"></a><h3><a name="g-date-get-julian"></a>g_date_get_julian ()</h3><a class="indexterm" name="id3153849"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint32">guint32</a> g_date_get_julian (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the Julian day or "serial number" of the <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. The
Julian day is simply the number of days since January 1, Year 1; i.e.,
January 1, Year 1 is Julian day 1; January 2, Year 1 is Julian day 2,
etc. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to extract the Julian day from.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>Julian day.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3153925"></a><h3><a name="g-date-get-weekday"></a>g_date_get_weekday ()</h3><a class="indexterm" name="id3153937"></a><pre class="programlisting"><a href="glib-Date-and-Time-Functions.html#GDateWeekday">GDateWeekday</a> g_date_get_weekday (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the day of the week for a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>day of the week as a <a href="glib-Date-and-Time-Functions.html#GDateWeekday"><span class="type">GDateWeekday</span></a>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154018"></a><h3><a name="g-date-get-day-of-year"></a>g_date_get_day_of_year ()</h3><a class="indexterm" name="id3154029"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a> g_date_get_day_of_year (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the day of the year, where Jan 1 is the first day of the
year. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to extract day of year from.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>day of the year.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154096"></a><h3><a name="g-date-get-days-in-month"></a>g_date_get_days_in_month ()</h3><a class="indexterm" name="id3154107"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint8">guint8</a> g_date_get_days_in_month (<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns the number of days in a month, taking leap years into account.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>number of days in <i class="parameter"><tt>month</tt></i> during the <i class="parameter"><tt>year</tt></i>.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154199"></a><h3><a name="g-date-is-first-of-month"></a>g_date_is_first_of_month ()</h3><a class="indexterm" name="id3154210"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_is_first_of_month (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns <tt class="literal">TRUE</tt> if the date is on the first of a month. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the date is the first of the month.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154287"></a><h3><a name="g-date-is-last-of-month"></a>g_date_is_last_of_month ()</h3><a class="indexterm" name="id3154298"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_is_last_of_month (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns <tt class="literal">TRUE</tt> if the date is the last day of the month. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the date is the last day of the month.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154375"></a><h3><a name="g-date-is-leap-year"></a>g_date_is_leap_year ()</h3><a class="indexterm" name="id3154387"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_is_leap_year (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns <tt class="literal">TRUE</tt> if the year is a leap year.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the year is a leap year.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154454"></a><h3><a name="g-date-get-monday-week-of-year"></a>g_date_get_monday_week_of_year ()</h3><a class="indexterm" name="id3154466"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a> g_date_get_monday_week_of_year (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the week of the year, where weeks are understood to start on
Monday. If the date is before the first Monday of the year, return
0. The date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>week of the year.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154534"></a><h3><a name="g-date-get-monday-weeks-in-year"></a>g_date_get_monday_weeks_in_year ()</h3><a class="indexterm" name="id3154546"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint8">guint8</a> g_date_get_monday_weeks_in_year (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns the number of weeks in the year, where weeks are taken to start
on Monday. Will be 52 or 53. The date must be valid. (Years always have 52
7-day periods, plus 1 or 2 extra days depending on whether it's a leap
year. This function is basically telling you how many Mondays are in
the year, i.e. there are 53 Mondays if one of the extra days happens
to be a Monday.)
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>a year.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>number of Mondays in the year.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154609"></a><h3><a name="g-date-get-sunday-week-of-year"></a>g_date_get_sunday_week_of_year ()</h3><a class="indexterm" name="id3154621"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint">guint</a> g_date_get_sunday_week_of_year (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns the week of the year during which this date falls, if weeks
are understood to being on Sunday. The date must be valid. Can return 0 if
the day is before the first Sunday of the year.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>week number.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154689"></a><h3><a name="g-date-get-sunday-weeks-in-year"></a>g_date_get_sunday_weeks_in_year ()</h3><a class="indexterm" name="id3154701"></a><pre class="programlisting"><a href="glib-Basic-Types.html#guint8">guint8</a> g_date_get_sunday_weeks_in_year (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns the number of weeks in the year, where weeks are taken to start
on Sunday. Will be 52 or 53. The date must be valid. (Years always have 52
7-day periods, plus 1 or 2 extra days depending on whether it's a leap
year. This function is basically telling you how many Sundays are in
the year, i.e. there are 53 Sundays if one of the extra days happens
to be a Sunday.)
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year to count weeks in.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>number of weeks.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154764"></a><h3><a name="g-date-strftime"></a>g_date_strftime ()</h3><a class="indexterm" name="id3154776"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gsize">gsize</a> g_date_strftime (<a href="glib-Basic-Types.html#gchar">gchar</a> *s,
<a href="glib-Basic-Types.html#gsize">gsize</a> slen,
const <a href="glib-Basic-Types.html#gchar">gchar</a> *format,
const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Generates a printed representation of the date, in a locale-specific
way. Works just like the standard C <tt class="function"><tt class="function">strftime()</tt></tt>
function, but only accepts date-related formats; time-related formats
give undefined results. Date must be valid.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>s</tt></i> :</span></td><td>destination buffer.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>slen</tt></i> :</span></td><td>buffer size.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>format</tt></i> :</span></td><td>format string.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>valid <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a>.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>number of characters written to the buffer, or 0 the buffer was too small.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3154923"></a><h3><a name="g-date-to-struct-tm"></a>g_date_to_struct_tm ()</h3><a class="indexterm" name="id3154934"></a><pre class="programlisting">void g_date_to_struct_tm (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date,
struct tm *tm);</pre><p>
Fills in the date-related bits of a <span class="structname">struct tm</span>
using the <i class="parameter"><tt>date</tt></i> value. Initializes the non-date parts with something
sane but meaningless.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to set the <span class="structname">struct tm</span> from.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>tm</tt></i> :</span></td><td><span class="structname">struct tm</span> to fill.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155027"></a><h3><a name="g-date-valid"></a>g_date_valid ()</h3><a class="indexterm" name="id3155038"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid (const <a href="glib-Date-and-Time-Functions.html#GDate">GDate</a> *date);</pre><p>
Returns <tt class="literal">TRUE</tt> if the <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> represents an existing day. The date must not
contain garbage; it should have been initialized with <a href="glib-Date-and-Time-Functions.html#g-date-clear"><tt class="function">g_date_clear()</tt></a>
if it wasn't allocated by one of the <a href="glib-Date-and-Time-Functions.html#g-date-new"><tt class="function">g_date_new()</tt></a> variants.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>date</tt></i> :</span></td><td>a <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td>Whether the date is valid.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155140"></a><h3><a name="g-date-valid-day"></a>g_date_valid_day ()</h3><a class="indexterm" name="id3155151"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_day (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day);</pre><p>
Returns <tt class="literal">TRUE</tt> if the day of the month is valid (a day is valid if it's
between 1 and 31 inclusive).
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>day</tt></i> :</span></td><td>day to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the day is valid.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155219"></a><h3><a name="g-date-valid-month"></a>g_date_valid_month ()</h3><a class="indexterm" name="id3155231"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_month (<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month);</pre><p>
Returns <tt class="literal">TRUE</tt> if the month value is valid. The 12 <a href="glib-Date-and-Time-Functions.html#GDateMonth"><span class="type">GDateMonth</span></a>
enumeration values are the only valid months.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the month is valid.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155307"></a><h3><a name="g-date-valid-year"></a>g_date_valid_year ()</h3><a class="indexterm" name="id3155319"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_year (<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns <tt class="literal">TRUE</tt> if the year is valid. Any year greater than 0 is valid,
though there is a 16-bit limit to what <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> will understand.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the year is valid.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155396"></a><h3><a name="g-date-valid-dmy"></a>g_date_valid_dmy ()</h3><a class="indexterm" name="id3155407"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_dmy (<a href="glib-Date-and-Time-Functions.html#GDateDay">GDateDay</a> day,
<a href="glib-Date-and-Time-Functions.html#GDateMonth">GDateMonth</a> month,
<a href="glib-Date-and-Time-Functions.html#GDateYear">GDateYear</a> year);</pre><p>
Returns <tt class="literal">TRUE</tt> if the day-month-year triplet forms a valid, existing day
in the range of days <a href="glib-Date-and-Time-Functions.html#GDate"><span class="type">GDate</span></a> understands (Year 1 or later, no more than
a few thousand years in the future).
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>day</tt></i> :</span></td><td>day.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>month</tt></i> :</span></td><td>month.
</td></tr><tr><td><span class="term"><i class="parameter"><tt>year</tt></i> :</span></td><td>year.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the date is a valid one.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155527"></a><h3><a name="g-date-valid-julian"></a>g_date_valid_julian ()</h3><a class="indexterm" name="id3155539"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_julian (<a href="glib-Basic-Types.html#guint32">guint32</a> julian_date);</pre><p>
Returns <tt class="literal">TRUE</tt> if the Julian day is valid. Anything greater than zero is basically a
valid Julian, though there is a 32-bit limit.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>julian_date</tt></i> :</span></td><td>Julian day to check.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the Julian day is valid.
</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3155608"></a><h3><a name="g-date-valid-weekday"></a>g_date_valid_weekday ()</h3><a class="indexterm" name="id3155620"></a><pre class="programlisting"><a href="glib-Basic-Types.html#gboolean">gboolean</a> g_date_valid_weekday (<a href="glib-Date-and-Time-Functions.html#GDateWeekday">GDateWeekday</a> weekday);</pre><p>
Returns <tt class="literal">TRUE</tt> if the weekday is valid. The 7 <a href="glib-Date-and-Time-Functions.html#GDateWeekday"><span class="type">GDateWeekday</span></a> enumeration
values are the only valid weekdays.
</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><span class="term"><i class="parameter"><tt>weekday</tt></i> :</span></td><td>weekday.
</td></tr><tr><td><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></td><td><tt class="literal">TRUE</tt> if the weekday is valid.
</td></tr></tbody></table></div></div></div></div><table class="navigation" width="100%" summary="Navigation footer" cellpadding="2" cellspacing="0"><tr valign="middle"><td align="left"><a accesskey="p" href="glib-I18N.html"><b><< Internationalization</b></a></td><td align="right"><a accesskey="n" href="glib-Random-Numbers.html"><b>Random Numbers >></b></a></td></tr></table></body></html>