A version of g_time_zone_new_identifier() which returns the UTC time zone
if identifier could not be parsed or loaded.
If you need to check whether identifier was loaded successfully, use
g_time_zone_new_identifier().
a timezone identifier
Finds an interval within tz that corresponds to the given time_,
possibly adjusting time_ if required to fit into an interval.
The meaning of time_ depends on type.
This function is similar to g_time_zone_find_interval(), with the difference that it always succeeds (by making the adjustments described below).
In any of the cases where g_time_zone_find_interval() succeeds then
this function returns the same value, without modifying time_.
This function may, however, modify time_ in order to deal with
non-existent times. If the non-existent local time_ of 02:30 were
requested on March 14th 2010 in Toronto then this function would
adjust time_ to be 03:00 and return the interval containing the
adjusted time.
the #GTimeType of time_
a pointer to a number of seconds since January 1, 1970
Finds an interval within tz that corresponds to the given time_.
The meaning of time_ depends on type.
If type is %G_TIME_TYPE_UNIVERSAL then this function will always
succeed (since universal time is monotonic and continuous).
Otherwise time_ is treated as local time. The distinction between
%G_TIME_TYPE_STANDARD and %G_TIME_TYPE_DAYLIGHT is ignored except in
the case that the given time_ is ambiguous. In Toronto, for example,
01:30 on November 7th 2010 occurred twice (once inside of daylight
savings time and the next, an hour later, outside of daylight savings
time). In this case, the different value of type would result in a
different interval being returned.
It is still possible for this function to fail. In Toronto, for example, 02:00 on March 14th 2010 does not exist (due to the leap forward to begin daylight savings time). -1 is returned in that case.
the #GTimeType of time_
a number of seconds since January 1, 1970
Determines the time zone abbreviation to be used during a particular
interval of time in the time zone tz.
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.
an interval within the timezone
Get the identifier of this #GTimeZone, as passed to g_time_zone_new().
If the identifier passed at construction time was not recognised, UTC will
be returned. If it was %NULL, the identifier of the local timezone at
construction time will be returned.
The identifier will be returned in the same format as provided at construction time: if provided as a time offset, that will be returned by this function.
Determines the offset to UTC in effect during a particular interval
of time in the time zone tz.
The offset is the number of seconds that you add to UTC time to
arrive at local time for tz (ie: negative numbers for time zones
west of GMT, positive numbers for east).
an interval within the timezone
Determines if daylight savings time is in effect during a particular
interval of time in the time zone tz.
an interval within the timezone
Increases the reference count on tz.
Decreases the reference count on tz.
A version of g_time_zone_new_identifier() which returns the UTC time zone
if identifier could not be parsed or loaded.
If you need to check whether identifier was loaded successfully, use
g_time_zone_new_identifier().
a timezone identifier
Creates a #GTimeZone corresponding to identifier. If identifier cannot be
parsed or loaded, %NULL is returned.
identifier can either be an RFC3339/ISO 8601 time offset or
something that would pass as a valid value for the TZ environment
variable (including %NULL).
In Windows, identifier can also be the unlocalized name of a time
zone for standard time, for example "Pacific Standard Time".
Valid RFC3339 time offsets are "Z" (for UTC) or
"±hh:mm". ISO 8601 additionally specifies
"±hhmm" and "±hh". Offsets are
time values to be added to Coordinated Universal Time (UTC) to get
the local time.
In UNIX, the TZ environment variable typically corresponds
to the name of a file in the zoneinfo database, an absolute path to a file
somewhere else, or a string in
"std offset [dst [offset],start[/time],end[/time]]" (POSIX) format.
There are no spaces in the specification. The name of standard
and daylight savings time zone must be three or more alphabetic
characters. Offsets are time values to be added to local time to
get Coordinated Universal Time (UTC) and should be
"[±]hh[[:]mm[:ss]]". Dates are either
"Jn" (Julian day with n between 1 and 365, leap
years not counted), "n" (zero-based Julian day
with n between 0 and 365) or "Mm.w.d" (day d
(0 <= d <= 6) of week w (1 <= w <= 5) of month m (1 <= m <= 12), day
0 is a Sunday). Times are in local wall clock time, the default is
02:00:00.
In Windows, the "tzn[+|–]hh[:mm[:ss]][dzn]" format is used, but also accepts POSIX format. The Windows format uses US rules for all time zones; daylight savings time is 60 minutes behind the standard time with date and time of change taken from Pacific Standard Time. Offsets are time values to be added to the local time to get Coordinated Universal Time (UTC).
g_time_zone_new_local() calls this function with the value of the
TZ environment variable. This function itself is independent of
the value of TZ, but if identifier is %NULL then /etc/localtime
will be consulted to discover the correct time zone on UNIX and the
registry will be consulted or GetTimeZoneInformation() will be used
to get the local time zone on Windows.
If intervals are not available, only time zone rules from TZ
environment variable or other means, then they will be computed
from year 1900 to 2037. If the maximum year for the rules is
available and it is greater than 2037, then it will followed
instead.
See
RFC3339 §5.6
for a precise definition of valid RFC3339 time offsets
(the time-offset expansion) and ISO 8601 for the
full list of valid time offsets. See
The GNU C Library manual
for an explanation of the possible
values of the TZ environment variable. See
Microsoft Time Zone Index Values
for the list of time zones on Windows.
You should release the return value by calling g_time_zone_unref() when you are done with it.
a timezone identifier
Creates a #GTimeZone corresponding to local time. The local time zone may change between invocations to this function; for example, if the system administrator changes it.
This is equivalent to calling g_time_zone_new() with the value of
the TZ environment variable (including the possibility of %NULL).
You should release the return value by calling g_time_zone_unref() when you are done with it.
Creates a #GTimeZone corresponding to the given constant offset from UTC, in seconds.
This is equivalent to calling g_time_zone_new() with a string in the form
[+|-]hh[:mm[:ss]].
offset to UTC, in seconds
Creates a #GTimeZone corresponding to UTC.
This is equivalent to calling g_time_zone_new() with a value like "Z", "UTC", "+00", etc.
You should release the return value by calling g_time_zone_unref() when you are done with it.
#GTimeZone is an opaque structure whose members cannot be accessed directly.