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GLib.TimeZone

record (struct)

A GTimeZone represents a time zone, at no particular point in time.

The GTimeZone struct is refcounted and immutable.

Each time zone has an identifier (for example, ‘Europe/London’) which is platform dependent. See TimeZone.new for information on the identifier formats. The identifier of a time zone can be retrieved using TimeZone.get_identifier.

A time zone contains a number of intervals. Each interval has an abbreviation to describe it (for example, ‘PDT’), an offset to UTC and a flag indicating if the daylight savings time is in effect during that interval. A time zone always has at least one interval — interval 0. Note that interval abbreviations are not the same as time zone identifiers (apart from ‘UTC’), and cannot be passed to TimeZone.new.

Every UTC time is contained within exactly one interval, but a given local time may be contained within zero, one or two intervals (due to incontinuities associated with daylight savings time).

An interval may refer to a specific period of time (eg: the duration of daylight savings time during 2010) or it may refer to many periods of time that share the same properties (eg: all periods of daylight savings time). It is also possible (usually for political reasons) that some properties (like the abbreviation) change between intervals without other properties changing.

Constructors

new

@classmethod
def new(cls, identifier: str | None = ...) -> TimeZone

:::warning Deprecated since 2.68 This API is deprecated. :::

A version of TimeZone.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 TimeZone.new_identifier.

Parameters:

  • identifier — a timezone identifier

new_identifier

@classmethod
def new_identifier(cls, identifier: str | None = ...) -> TimeZone | None

Creates a TimeZone corresponding to identifier. If identifier cannot be parsed or loaded, None 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 None).

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).

TimeZone.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 None 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 TimeZone.unref when you are done with it.

Parameters:

  • identifier — a timezone identifier

new_local

@classmethod
def new_local(cls) -> TimeZone

Creates a TimeZone 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 TimeZone.new with the value of the TZ environment variable (including the possibility of None).

You should release the return value by calling TimeZone.unref when you are done with it.

new_offset

@classmethod
def new_offset(cls, seconds: int) -> TimeZone

Creates a TimeZone corresponding to the given constant offset from UTC, in seconds.

This is equivalent to calling TimeZone.new with a string in the form [+|-]hh[:mm[:ss]].

It is possible for this function to fail if seconds is too big (greater than 24 hours), in which case this function will return the UTC timezone for backwards compatibility. To detect failures like this, use TimeZone.new_identifier directly.

Parameters:

  • seconds — offset to UTC, in seconds

new_utc

@classmethod
def new_utc(cls) -> TimeZone

Creates a TimeZone corresponding to UTC.

This is equivalent to calling TimeZone.new with a value like "Z", "UTC", "+00", etc.

You should release the return value by calling TimeZone.unref when you are done with it.

Methods

adjust_time

def adjust_time(self, type: TimeType | int, time_: int) -> tuple[int, int]

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 TimeZone.find_interval, with the difference that it always succeeds (by making the adjustments described below).

In any of the cases where TimeZone.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.

Parameters:

  • type — the TimeType of time_
  • time_ — a pointer to a number of seconds since January 1, 1970

find_interval

def find_interval(self, type: TimeType | int, time_: int) -> int

Finds an interval within tz that corresponds to the given time_. The meaning of time_ depends on type.

If type is TimeType.UNIVERSAL then this function will always succeed (since universal time is monotonic and continuous).

Otherwise time_ is treated as local time. The distinction between TimeType.STANDARD and TimeType.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.

Parameters:

  • type — the TimeType of time_
  • time_ — a number of seconds since January 1, 1970

get_abbreviation

def get_abbreviation(self, interval: int) -> str

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.

Parameters:

  • interval — an interval within the timezone

get_identifier

def get_identifier(self) -> str

Get the identifier of this TimeZone, as passed to TimeZone.new. If the identifier passed at construction time was not recognised, UTC will be returned. If it was None, 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.

get_offset

def get_offset(self, interval: int) -> int

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).

Parameters:

  • interval — an interval within the timezone

is_dst

def is_dst(self, interval: int) -> bool

Determines if daylight savings time is in effect during a particular interval of time in the time zone tz.

Parameters:

  • interval — an interval within the timezone

ref

def ref(self) -> TimeZone

Increases the reference count on tz.

unref

def unref(self) -> None

Decreases the reference count on tz.