## GstDateTime

GstDateTime — A date, time and timezone structure

## Synopsis

    #include <gst/gst.h>

                        GstDateTime;
    #define             GST_TYPE_DATE_TIME
    gint                gst_date_time_get_day               (const GstDateTime *datetime);
    gint                gst_date_time_get_month             (const GstDateTime *datetime);
    gint                gst_date_time_get_hour              (const GstDateTime *datetime);
    gint                gst_date_time_get_microsecond       (const GstDateTime *datetime);
    gint                gst_date_time_get_minute            (const GstDateTime *datetime);
    gfloat              gst_date_time_get_time_zone_offset  (const GstDateTime *datetime);
    gint                gst_date_time_get_second            (const GstDateTime *datetime);
    gint                gst_date_time_get_year              (const GstDateTime *datetime);
    GstDateTime *       gst_date_time_new                   (gfloat tzoffset,
                                                             gint year,
                                                             gint month,
                                                             gint day,
                                                             gint hour,
                                                             gint minute,
                                                             gdouble seconds);
    GstDateTime *       gst_date_time_new_ymd               (gint year,
                                                             gint month,
                                                             gint day);
    GstDateTime *       gst_date_time_new_ym                (gint year,
                                                             gint month);
    GstDateTime *       gst_date_time_new_y                 (gint year);
    GstDateTime *       gst_date_time_new_from_unix_epoch_local_time
                                                            (gint64 secs);
    GstDateTime *       gst_date_time_new_from_unix_epoch_utc
                                                            (gint64 secs);
    GstDateTime *       gst_date_time_new_local_time        (gint year,
                                                             gint month,
                                                             gint day,
                                                             gint hour,
                                                             gint minute,
                                                             gdouble seconds);
    GstDateTime *       gst_date_time_new_now_local_time    (void);
    GstDateTime *       gst_date_time_new_now_utc           (void);
    GstDateTime *       gst_date_time_ref                   (GstDateTime *datetime);
    void                gst_date_time_unref                 (GstDateTime *datetime);
    gboolean            gst_date_time_has_day               (const GstDateTime *datetime);
    gboolean            gst_date_time_has_month             (const GstDateTime *datetime);
    gboolean            gst_date_time_has_second            (const GstDateTime *datetime);
    gboolean            gst_date_time_has_time              (const GstDateTime *datetime);
    gboolean            gst_date_time_has_year              (const GstDateTime *datetime);
    GstDateTime *       gst_date_time_new_from_iso8601_string
                                                            (const gchar *string);
    gchar *             gst_date_time_to_iso8601_string     (GstDateTime *datetime);
    GstDateTime *       gst_date_time_new_from_g_date_time  (GDateTime *dt);
    GDateTime *         gst_date_time_to_g_date_time        (GstDateTime *datetime);

## Description

Struct to store date, time and timezone information altogether. GstDateTime is refcounted and immutable.

Date information is handled using the proleptic Gregorian calendar.

Provides basic creation functions and accessor functions to its fields.

## Details

### GstDateTime

    typedef struct _GstDateTime GstDateTime;

Opaque, immutable, refcounted struct that stores date, time and timezone information. It currently supports ranges from 0001-01-01 to 9999-12-31 in the Gregorian proleptic calendar.

Use the acessor functions to get the stored values.

### GST_TYPE_DATE_TIME

    #define GST_TYPE_DATE_TIME               gst_date_time_get_type ()

a boxed GValue type for GstDateTime that represents a date and time.

Returns : | the GType of GstDateTime

### gst_date_time_get_day ()

    gint                gst_date_time_get_day               (const GstDateTime *datetime);

Returns the day of the month of this GstDateTime. Call gst_date_time_has_day before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | The day of this GstDateTime

### gst_date_time_get_month ()

    gint                gst_date_time_get_month             (const GstDateTime *datetime);

Returns the month of this GstDateTime. January is 1, February is 2, etc.. Call gst_date_time_has_month before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | The month of this GstDateTime

### gst_date_time_get_hour ()

    gint                gst_date_time_get_hour              (const GstDateTime *datetime);

Retrieves the hour of the day represented by `datetime` in the gregorian calendar. The return is in the range of 0 to 23. Call gst_date_time_has_haur before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | the hour of the day

### gst_date_time_get_microsecond ()

    gint                gst_date_time_get_microsecond       (const GstDateTime *datetime);

Retrieves the fractional part of the seconds in microseconds represented by `datetime` in the gregorian calendar.

`datetime` : | a GstDateTime
Returns : | the microsecond of the second

### gst_date_time_get_minute ()

    gint                gst_date_time_get_minute            (const GstDateTime *datetime);

Retrieves the minute of the hour represented by `datetime` in the gregorian calendar. Call gst_date_time_has_minute before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | the minute of the hour

### gst_date_time_get_time_zone_offset ()

    gfloat              gst_date_time_get_time_zone_offset  (const GstDateTime *datetime);

Retrieves the offset from UTC in hours that the timezone specified by `datetime` represents. Timezones ahead (to the east) of UTC have positive values, timezones before (to the west) of UTC have negative values. If `datetime` represents UTC time, then the offset is zero.

`datetime` : | a GstDateTime
Returns : | the offset from UTC in hours

### gst_date_time_get_second ()

    gint                gst_date_time_get_second            (const GstDateTime *datetime);

Retrieves the second of the minute represented by `datetime` in the gregorian calendar. Call gst_date_time_has_second before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | the second represented by `datetime`

### gst_date_time_get_year ()

    gint                gst_date_time_get_year              (const GstDateTime *datetime);

Returns the year of this GstDateTime Call gst_date_time_has_year before, to avoid warnings.

`datetime` : | a GstDateTime
Returns : | The year of this GstDateTime

### gst_date_time_new ()

    GstDateTime *       gst_date_time_new                   (gfloat tzoffset,
                                                             gint year,
                                                             gint month,
                                                             gint day,
                                                             gint hour,
                                                             gint minute,
                                                             gdouble seconds);

Creates a new GstDateTime using the date and times in the gregorian calendar in the supplied timezone.

`year` should be from 1 to 9999, `month` should be from 1 to 12, `day` from 1 to 31, `hour` from 0 to 23, `minutes` and `seconds` from 0 to 59.

Note that `tzoffset` is a float and was chosen so for being able to handle some fractional timezones, while it still keeps the readability of represeting it in hours for most timezones.

If value is -1 then all over value will be ignored. For example if `month` == -1, then GstDateTime will created only for `year`. If `day` == -1, then GstDateTime will created for `year` and `month` and so on.

Free-function: gst_date_time_unref

`tzoffset` : | Offset from UTC in hours.
`year` : | the gregorian year
`month` : | the gregorian month
`day` : | the day of the gregorian month
`hour` : | the hour of the day
`minute` : | the minute of the hour
`seconds` : | the second of the minute
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_ymd ()

    GstDateTime *       gst_date_time_new_ymd               (gint year,
                                                             gint month,
                                                             gint day);

Creates a new GstDateTime using the date and times in the gregorian calendar in the local timezone.

`year` should be from 1 to 9999, `month` should be from 1 to 12, `day` from 1 to 31.

If value is -1 then all over value will be ignored. For example if `month` == -1, then GstDateTime will created only for `year`. If `day` == -1, then GstDateTime will created for `year` and `month` and so on.

Free-function: gst_date_time_unref

`year` : | the gregorian year
`month` : | the gregorian month
`day` : | the day of the gregorian month
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_ym ()

    GstDateTime *       gst_date_time_new_ym                (gint year,
                                                             gint month);

Creates a new GstDateTime using the date and times in the gregorian calendar in the local timezone.

`year` should be from 1 to 9999, `month` should be from 1 to 12.

If value is -1 then all over value will be ignored. For example if `month` == -1, then GstDateTime will created only for `year`.

Free-function: gst_date_time_unref

`year` : | the gregorian year
`month` : | the gregorian month
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_y ()

    GstDateTime *       gst_date_time_new_y                 (gint year);

Creates a new GstDateTime using the date and times in the gregorian calendar in the local timezone.

`year` should be from 1 to 9999.

Free-function: gst_date_time_unref

`year` : | the gregorian year
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_from_unix_epoch_local_time ()

    GstDateTime *       gst_date_time_new_from_unix_epoch_local_time
                                                            (gint64 secs);

Creates a new GstDateTime using the time since Jan 1, 1970 specified by `secs`. The GstDateTime is in the local timezone.

Free-function: gst_date_time_unref

`secs` : | seconds from the Unix epoch
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_from_unix_epoch_utc ()

    GstDateTime *       gst_date_time_new_from_unix_epoch_utc
                                                            (gint64 secs);

Creates a new GstDateTime using the time since Jan 1, 1970 specified by `secs`. The GstDateTime is in the UTC timezone.

Free-function: gst_date_time_unref

`secs` : | seconds from the Unix epoch
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_local_time ()

    GstDateTime *       gst_date_time_new_local_time        (gint year,
                                                             gint month,
                                                             gint day,
                                                             gint hour,
                                                             gint minute,
                                                             gdouble seconds);

Creates a new GstDateTime using the date and times in the gregorian calendar in the local timezone.

`year` should be from 1 to 9999, `month` should be from 1 to 12, `day` from 1 to 31, `hour` from 0 to 23, `minutes` and `seconds` from 0 to 59.

If `month` is -1, then the GstDateTime created will only contain `year`, and all other fields will be considered not set.

If `day` is -1, then the GstDateTime created will only contain `year` and `month` and all other fields will be considered not set.

If `hour` is -1, then the GstDateTime created will only contain `year` and `month` and `day`, and the time fields will be considered not set. In this case `minute` and `seconds` should also be -1.

Free-function: gst_date_time_unref

`year` : | the gregorian year
`month` : | the gregorian month, or -1
`day` : | the day of the gregorian month, or -1
`hour` : | the hour of the day, or -1
`minute` : | the minute of the hour, or -1
`seconds` : | the second of the minute, or -1
Returns : | the newly created GstDateTime. [transfer full]

### gst_date_time_new_now_local_time ()

    GstDateTime *       gst_date_time_new_now_local_time    (void);

Creates a new GstDateTime representing the current date and time.

Free-function: gst_date_time_unref

Returns : | the newly created GstDateTime which should be freed with `gst_date_time_unref()`. [transfer full]

### gst_date_time_new_now_utc ()

    GstDateTime *       gst_date_time_new_now_utc           (void);

Creates a new GstDateTime that represents the current instant at Universal coordinated time.

Free-function: gst_date_time_unref

Returns : | the newly created GstDateTime which should be freed with `gst_date_time_unref()`. [transfer full]

### gst_date_time_ref ()

    GstDateTime *       gst_date_time_ref                   (GstDateTime *datetime);

Atomically increments the reference count of `datetime` by one.

`datetime` : | a GstDateTime
Returns : | the reference `datetime`. [transfer full]

### gst_date_time_unref ()

    void                gst_date_time_unref                 (GstDateTime *datetime);

Atomically decrements the reference count of `datetime` by one. When the reference count reaches zero, the structure is freed.

`datetime` : | a GstDateTime. [transfer full]

### gst_date_time_has_day ()

    gboolean            gst_date_time_has_day               (const GstDateTime *datetime);

`datetime` : | a GstDateTime
Returns : | TRUE if `datetime`'s day field is set, otherwise FALSE

### gst_date_time_has_month ()

    gboolean            gst_date_time_has_month             (const GstDateTime *datetime);

`datetime` : | a GstDateTime
Returns : | TRUE if `datetime`'s month field is set, otherwise FALSE

### gst_date_time_has_second ()

    gboolean            gst_date_time_has_second            (const GstDateTime *datetime);

`datetime` : | a GstDateTime
Returns : | TRUE if `datetime`'s second field is set, otherwise FALSE

### gst_date_time_has_time ()

    gboolean            gst_date_time_has_time              (const GstDateTime *datetime);

`datetime` : | a GstDateTime
Returns : | TRUE if `datetime`'s hour and minute fields are set, otherwise FALSE

### gst_date_time_has_year ()

    gboolean            gst_date_time_has_year              (const GstDateTime *datetime);

`datetime` : | a GstDateTime
Returns : | TRUE if `datetime`'s year field is set (which should always be the case), otherwise FALSE

### gst_date_time_new_from_iso8601_string ()

    GstDateTime *       gst_date_time_new_from_iso8601_string
                                                            (const gchar *string);

Tries to parse common variants of ISO-8601 datetime strings into a GstDateTime.

Free-function: gst_date_time_unref

`string` : | ISO 8601-formatted datetime string.
Returns : | a newly created GstDateTime, or NULL on error. [transfer full]

### gst_date_time_to_iso8601_string ()

    gchar *             gst_date_time_to_iso8601_string     (GstDateTime *datetime);

Create a minimal string compatible with ISO-8601. Possible output formats are (for example): 2012, 2012-06, 2012-06-23, 2012-06-23T23:30Z, 2012-06-23T23:30+0100, 2012-06-23T23:30:59Z, 2012-06-23T23:30:59+0100

`datetime` : | GstDateTime.
Returns : | a newly allocated string formatted according to ISO 8601 and only including the datetime fields that are valid, or NULL in case there was an error. The string should be freed with `g_free()`.

### gst_date_time_new_from_g_date_time ()

    GstDateTime *       gst_date_time_new_from_g_date_time  (GDateTime *dt);

Creates a new GstDateTime from a GDateTime object.

Free-function: gst_date_time_unref

`dt` : | the GDateTime. The new GstDateTime takes ownership. [transfer full]
Returns : | a newly created GstDateTime, or NULL on error. [transfer full]

### gst_date_time_to_g_date_time ()

    GDateTime *         gst_date_time_to_g_date_time        (GstDateTime *datetime);

Creates a new GDateTime from a fully defined GstDateTime object.

Free-function: g_date_time_unref

`datetime` : | GstDateTime.
Returns : | a newly created GDateTime, or NULL on error. [transfer full]