g_date_time_unref ()

void
g_date_time_unref (GDateTime *datetime);

Atomically decrements the reference count of datetime by one.

When the reference count reaches zero, the resources allocated by datetime are freed

Since: 2.26

g_date_time_ref ()

GDateTime *
g_date_time_ref (GDateTime *datetime);

Atomically increments the reference count of datetime by one.

Since: 2.26

g_date_time_new_now ()

GDateTime *
g_date_time_new_now (GTimeZone *tz);

Creates a GDateTime corresponding to this exact instant in the given time zone tz . The time is as accurate as the system allows, to a maximum accuracy of 1 microsecond.

This function will always succeed unless GLib is still being used after the year 9999.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_now_local ()

GDateTime *
g_date_time_new_now_local (void);

Creates a GDateTime corresponding to this exact instant in the local time zone.

This is equivalent to calling g_date_time_new_now() with the time zone returned by g_time_zone_new_local().

[constructor]

Since: 2.26

g_date_time_new_now_utc ()

GDateTime *
g_date_time_new_now_utc (void);

Creates a GDateTime corresponding to this exact instant in UTC.

This is equivalent to calling g_date_time_new_now() with the time zone returned by g_time_zone_new_utc().

[constructor]

Since: 2.26

g_date_time_new_from_unix_local ()

GDateTime *
g_date_time_new_from_unix_local (gint64 t);

Creates a GDateTime corresponding to the given Unix time t in the local time zone.

Unix time is the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC, regardless of the local time offset.

This call can fail (returning NULL) if t represents a time outside of the supported range of GDateTime.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_from_unix_utc ()

GDateTime *
g_date_time_new_from_unix_utc (gint64 t);

Creates a GDateTime corresponding to the given Unix time t in UTC.

Unix time is the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC.

This call can fail (returning NULL) if t represents a time outside of the supported range of GDateTime.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_from_timeval_local ()

GDateTime *
g_date_time_new_from_timeval_local (const GTimeVal *tv);

Creates a GDateTime corresponding to the given GTimeVal tv in the local time zone.

The time contained in a GTimeVal is always stored in the form of seconds elapsed since 1970-01-01 00:00:00 UTC, regardless of the local time offset.

This call can fail (returning NULL) if tv represents a time outside of the supported range of GDateTime.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_from_timeval_utc ()

GDateTime *
g_date_time_new_from_timeval_utc (const GTimeVal *tv);

Creates a GDateTime corresponding to the given GTimeVal tv in UTC.

The time contained in a GTimeVal is always stored in the form of seconds elapsed since 1970-01-01 00:00:00 UTC.

This call can fail (returning NULL) if tv represents a time outside of the supported range of GDateTime.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_from_iso8601 ()

GDateTime *
g_date_time_new_from_iso8601 (const gchar *text,
                              GTimeZone *default_tz);

Creates a GDateTime corresponding to the given ISO 8601 formatted string text . ISO 8601 strings of the form <date><sep><time><tz> are supported, with some extensions from RFC 3339 as mentioned below.

Note that as GDateTime "is oblivious to leap seconds", leap seconds information in an ISO-8601 string will be ignored, so a 23:59:60 time would be parsed as 23:59:59.

<sep> is the separator and can be either 'T', 't' or ' '. The latter two separators are an extension from RFC 3339.

<date> is in the form:

<time> is in the form:

<tz> is an optional timezone suffix of the form:

If the timezone is not provided in text it must be provided in default_tz (this field is otherwise ignored).

This call can fail (returning NULL) if text is not a valid ISO 8601 formatted string.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.56

g_date_time_new ()

GDateTime *
g_date_time_new (GTimeZone *tz,
                 gint year,
                 gint month,
                 gint day,
                 gint hour,
                 gint minute,
                 gdouble seconds);

Creates a new GDateTime corresponding to the given date and time in the time zone tz .

The year must be between 1 and 9999, month between 1 and 12 and day between 1 and 28, 29, 30 or 31 depending on the month and the year.

hour must be between 0 and 23 and minute must be between 0 and 59.

seconds must be at least 0.0 and must be strictly less than 60.0. It will be rounded down to the nearest microsecond.

If the given time is not representable in the given time zone (for example, 02:30 on March 14th 2010 in Toronto, due to daylight savings time) then the time will be rounded up to the nearest existing time (in this case, 03:00). If this matters to you then you should verify the return value for containing the same as the numbers you gave.

In the case that the given time is ambiguous in the given time zone (for example, 01:30 on November 7th 2010 in Toronto, due to daylight savings time) then the time falling within standard (ie: non-daylight) time is taken.

It not considered a programmer error for the values to this function to be out of range, but in the case that they are, the function will return NULL.

You should release the return value by calling g_date_time_unref() when you are done with it.

[constructor]

Since: 2.26

g_date_time_new_local ()

GDateTime *
g_date_time_new_local (gint year,
                       gint month,
                       gint day,
                       gint hour,
                       gint minute,
                       gdouble seconds);

Creates a new GDateTime corresponding to the given date and time in the local time zone.

This call is equivalent to calling g_date_time_new() with the time zone returned by g_time_zone_new_local().

[constructor]

Since: 2.26

g_date_time_new_utc ()

GDateTime *
g_date_time_new_utc (gint year,
                     gint month,
                     gint day,
                     gint hour,
                     gint minute,
                     gdouble seconds);

Creates a new GDateTime corresponding to the given date and time in UTC.

This call is equivalent to calling g_date_time_new() with the time zone returned by g_time_zone_new_utc().

[constructor]

Since: 2.26

g_date_time_add ()

GDateTime *
g_date_time_add (GDateTime *datetime,
                 GTimeSpan timespan);

Creates a copy of datetime and adds the specified timespan to the copy.

Since: 2.26

g_date_time_add_years ()

GDateTime *
g_date_time_add_years (GDateTime *datetime,
                       gint years);

Creates a copy of datetime and adds the specified number of years to the copy. Add negative values to subtract years.

As with g_date_time_add_months(), if the resulting date would be 29th February on a non-leap year, the day will be clamped to 28th February.

Since: 2.26

g_date_time_add_months ()

GDateTime *
g_date_time_add_months (GDateTime *datetime,
                        gint months);

Creates a copy of datetime and adds the specified number of months to the copy. Add negative values to subtract months.

The day of the month of the resulting GDateTime is clamped to the number of days in the updated calendar month. For example, if adding 1 month to 31st January 2018, the result would be 28th February 2018. In 2020 (a leap year), the result would be 29th February.

Since: 2.26

g_date_time_add_weeks ()

GDateTime *
g_date_time_add_weeks (GDateTime *datetime,
                       gint weeks);

Creates a copy of datetime and adds the specified number of weeks to the copy. Add negative values to subtract weeks.

Since: 2.26

g_date_time_add_days ()

GDateTime *
g_date_time_add_days (GDateTime *datetime,
                      gint days);

Creates a copy of datetime and adds the specified number of days to the copy. Add negative values to subtract days.

Since: 2.26

g_date_time_add_hours ()

GDateTime *
g_date_time_add_hours (GDateTime *datetime,
                       gint hours);

Creates a copy of datetime and adds the specified number of hours. Add negative values to subtract hours.

Since: 2.26

g_date_time_add_minutes ()

GDateTime *
g_date_time_add_minutes (GDateTime *datetime,
                         gint minutes);

Creates a copy of datetime adding the specified number of minutes. Add negative values to subtract minutes.

Since: 2.26

g_date_time_add_seconds ()

GDateTime *
g_date_time_add_seconds (GDateTime *datetime,
                         gdouble seconds);

Creates a copy of datetime and adds the specified number of seconds. Add negative values to subtract seconds.

Since: 2.26

g_date_time_add_full ()

GDateTime *
g_date_time_add_full (GDateTime *datetime,
                      gint years,
                      gint months,
                      gint days,
                      gint hours,
                      gint minutes,
                      gdouble seconds);

Creates a new GDateTime adding the specified values to the current date and time in datetime . Add negative values to subtract.

Since: 2.26

g_date_time_compare ()

gint
g_date_time_compare (gconstpointer dt1,
                     gconstpointer dt2);

A comparison function for GDateTimes that is suitable as a GCompareFunc. Both GDateTimes must be non-NULL.

Since: 2.26

g_date_time_difference ()

GTimeSpan
g_date_time_difference (GDateTime *end,
                        GDateTime *begin);

Calculates the difference in time between end and begin . The GTimeSpan that is returned is effectively end - begin (ie: positive if the first parameter is larger).

Since: 2.26

g_date_time_hash ()

guint
g_date_time_hash (gconstpointer datetime);

Hashes datetime into a guint, suitable for use within GHashTable.

Since: 2.26

g_date_time_equal ()

gboolean
g_date_time_equal (gconstpointer dt1,
                   gconstpointer dt2);

Checks to see if dt1 and dt2 are equal.

Equal here means that they represent the same moment after converting them to the same time zone.

Since: 2.26

g_date_time_get_ymd ()

void
g_date_time_get_ymd (GDateTime *datetime,
                     gint *year,
                     gint *month,
                     gint *day);

Retrieves the Gregorian day, month, and year of a given GDateTime.

Since: 2.26

g_date_time_get_year ()

gint
g_date_time_get_year (GDateTime *datetime);

Retrieves the year represented by datetime in the Gregorian calendar.

Since: 2.26

g_date_time_get_month ()

gint
g_date_time_get_month (GDateTime *datetime);

Retrieves the month of the year represented by datetime in the Gregorian calendar.

Since: 2.26

g_date_time_get_day_of_month ()

gint
g_date_time_get_day_of_month (GDateTime *datetime);

Retrieves the day of the month represented by datetime in the gregorian calendar.

Since: 2.26

g_date_time_get_week_numbering_year ()

gint
g_date_time_get_week_numbering_year (GDateTime *datetime);

Returns the ISO 8601 week-numbering year in which the week containing datetime falls.

This function, taken together with g_date_time_get_week_of_year() and g_date_time_get_day_of_week() can be used to determine the full ISO week date on which datetime falls.

This is usually equal to the normal Gregorian year (as returned by g_date_time_get_year()), except as detailed below:

For Thursday, the week-numbering year is always equal to the usual calendar year. For other days, the number is such that every day within a complete week (Monday to Sunday) is contained within the same week-numbering year.

For Monday, Tuesday and Wednesday occurring near the end of the year, this may mean that the week-numbering year is one greater than the calendar year (so that these days have the same week-numbering year as the Thursday occurring early in the next year).

For Friday, Saturday and Sunday occurring near the start of the year, this may mean that the week-numbering year is one less than the calendar year (so that these days have the same week-numbering year as the Thursday occurring late in the previous year).

An equivalent description is that the week-numbering year is equal to the calendar year containing the majority of the days in the current week (Monday to Sunday).

Note that January 1 0001 in the proleptic Gregorian calendar is a Monday, so this function never returns 0.

Since: 2.26

g_date_time_get_week_of_year ()

gint
g_date_time_get_week_of_year (GDateTime *datetime);

Returns the ISO 8601 week number for the week containing datetime . The ISO 8601 week number is the same for every day of the week (from Moday through Sunday). That can produce some unusual results (described below).

The first week of the year is week 1. This is the week that contains the first Thursday of the year. Equivalently, this is the first week that has more than 4 of its days falling within the calendar year.

The value 0 is never returned by this function. Days contained within a year but occurring before the first ISO 8601 week of that year are considered as being contained in the last week of the previous year. Similarly, the final days of a calendar year may be considered as being part of the first ISO 8601 week of the next year if 4 or more days of that week are contained within the new year.

Since: 2.26

g_date_time_get_day_of_week ()

gint
g_date_time_get_day_of_week (GDateTime *datetime);

Retrieves the ISO 8601 day of the week on which datetime falls (1 is Monday, 2 is Tuesday... 7 is Sunday).

Since: 2.26

g_date_time_get_day_of_year ()

gint
g_date_time_get_day_of_year (GDateTime *datetime);

Retrieves the day of the year represented by datetime in the Gregorian calendar.

Since: 2.26

g_date_time_get_hour ()

gint
g_date_time_get_hour (GDateTime *datetime);

Retrieves the hour of the day represented by datetime

Since: 2.26

g_date_time_get_minute ()

gint
g_date_time_get_minute (GDateTime *datetime);

Retrieves the minute of the hour represented by datetime

Since: 2.26

g_date_time_get_second ()

gint
g_date_time_get_second (GDateTime *datetime);

Retrieves the second of the minute represented by datetime

Since: 2.26

g_date_time_get_microsecond ()

gint
g_date_time_get_microsecond (GDateTime *datetime);

Retrieves the microsecond of the date represented by datetime

Since: 2.26

g_date_time_get_seconds ()

gdouble
g_date_time_get_seconds (GDateTime *datetime);

Retrieves the number of seconds since the start of the last minute, including the fractional part.

Since: 2.26

g_date_time_to_unix ()

gint64
g_date_time_to_unix (GDateTime *datetime);

Gives the Unix time corresponding to datetime , rounding down to the nearest second.

Unix time is the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC, regardless of the time zone associated with datetime .

Since: 2.26

g_date_time_to_timeval ()

gboolean
g_date_time_to_timeval (GDateTime *datetime,
                        GTimeVal *tv);

Stores the instant in time that datetime represents into tv .

The time contained in a GTimeVal is always stored in the form of seconds elapsed since 1970-01-01 00:00:00 UTC, regardless of the time zone associated with datetime .

On systems where 'long' is 32bit (ie: all 32bit systems and all Windows systems), a GTimeVal is incapable of storing the entire range of values that GDateTime is capable of expressing. On those systems, this function returns FALSE to indicate that the time is out of range.

On systems where 'long' is 64bit, this function never fails.

Since: 2.26

g_date_time_get_utc_offset ()

GTimeSpan
g_date_time_get_utc_offset (GDateTime *datetime);

Determines the offset to UTC in effect at the time and in the time zone of datetime .

The offset is the number of microseconds that you add to UTC time to arrive at local time for the time zone (ie: negative numbers for time zones west of GMT, positive numbers for east).

If datetime represents UTC time, then the offset is always zero.

Since: 2.26

g_date_time_get_timezone ()

GTimeZone *
g_date_time_get_timezone (GDateTime *datetime);

Get the time zone for this datetime .

Since: 2.58

g_date_time_get_timezone_abbreviation ()

const gchar *
g_date_time_get_timezone_abbreviation (GDateTime *datetime);

Determines the time zone abbreviation to be used at the time and in the time zone of datetime .

For example, in Toronto this is currently "EST" during the winter months and "EDT" during the summer months when daylight savings time is in effect.

Since: 2.26

g_date_time_is_daylight_savings ()

gboolean
g_date_time_is_daylight_savings (GDateTime *datetime);

Determines if daylight savings time is in effect at the time and in the time zone of datetime .

Since: 2.26

g_date_time_to_timezone ()

GDateTime *
g_date_time_to_timezone (GDateTime *datetime,
                         GTimeZone *tz);

Create a new GDateTime corresponding to the same instant in time as datetime , but in the time zone tz .

This call can fail in the case that the time goes out of bounds. For example, converting 0001-01-01 00:00:00 UTC to a time zone west of Greenwich will fail (due to the year 0 being out of range).

Since: 2.26

g_date_time_to_local ()

GDateTime *
g_date_time_to_local (GDateTime *datetime);

Creates a new GDateTime corresponding to the same instant in time as datetime , but in the local time zone.

This call is equivalent to calling g_date_time_to_timezone() with the time zone returned by g_time_zone_new_local().

Since: 2.26

g_date_time_to_utc ()

GDateTime *
g_date_time_to_utc (GDateTime *datetime);

Creates a new GDateTime corresponding to the same instant in time as datetime , but in UTC.

This call is equivalent to calling g_date_time_to_timezone() with the time zone returned by g_time_zone_new_utc().

Since: 2.26

g_date_time_format ()

gchar *
g_date_time_format (GDateTime *datetime,
                    const gchar *format);

Creates a newly allocated string representing the requested format .

The format strings understood by this function are a subset of the strftime() format language as specified by C99. The %D, %U and %W conversions are not supported, nor is the 'E' modifier. The GNU extensions %k, %l, %s and %P are supported, however, as are the '0', '_' and '-' modifiers. The Python extension %f is also supported.

In contrast to strftime(), this function always produces a UTF-8 string, regardless of the current locale. Note that the rendering of many formats is locale-dependent and may not match the strftime() output exactly.

The following format specifiers are supported:

Some conversion specifications can be modified by preceding the conversion specifier by one or more modifier characters. The following modifiers are supported for many of the numeric conversions:

Additionally, when O is used with B, b, or h, it produces the alternative form of a month name. The alternative form should be used when the month name is used without a day number (e.g., standalone). It is required in some languages (Baltic, Slavic, Greek, and more) due to their grammatical rules. For other languages there is no difference. %OB is a GNU and BSD strftime() extension expected to be added to the future POSIX specification, %Ob and %Oh are GNU strftime() extensions. Since: 2.56

Since: 2.26

g_date_time_format_iso8601 ()

gchar *
g_date_time_format_iso8601 (GDateTime *datetime);

Format datetime in ISO 8601 format, including the date, time and time zone, and return that as a UTF-8 encoded string.

Since GLib 2.66, this will output to sub-second precision if needed.

Since: 2.62

GTimeSpan

typedef gint64 GTimeSpan;

A value representing an interval of time, in microseconds.

Since: 2.26

G_TIME_SPAN_DAY

#define G_TIME_SPAN_DAY                 (G_GINT64_CONSTANT (86400000000))

Evaluates to a time span of one day.

Since: 2.26

G_TIME_SPAN_HOUR

#define G_TIME_SPAN_HOUR                (G_GINT64_CONSTANT (3600000000))

Evaluates to a time span of one hour.

Since: 2.26

G_TIME_SPAN_MINUTE

#define G_TIME_SPAN_MINUTE              (G_GINT64_CONSTANT (60000000))

Evaluates to a time span of one minute.

Since: 2.26

G_TIME_SPAN_SECOND

#define G_TIME_SPAN_SECOND              (G_GINT64_CONSTANT (1000000))

Evaluates to a time span of one second.

Since: 2.26

G_TIME_SPAN_MILLISECOND

#define G_TIME_SPAN_MILLISECOND         (G_GINT64_CONSTANT (1000))

Evaluates to a time span of one millisecond.

Since: 2.26

GDateTime

typedef struct _GDateTime GDateTime;

An opaque structure that represents a date and time, including a time zone.

Since: 2.26