| Copyright | Will Thompson and Iñaki García Etxebarria |
|---|---|
| License | LGPL-2.1 |
| Maintainer | Iñaki García Etxebarria |
| Safe Haskell | Safe-Inferred |
| Language | Haskell2010 |
GI.GLib.Structs.TimeZone
Description
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 timeZoneNew for information on the
identifier formats. The identifier of a time zone can be retrieved using
timeZoneGetIdentifier.
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 timeZoneNew.
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.
Since: 2.26
Synopsis
- newtype TimeZone = TimeZone (ManagedPtr TimeZone)
- timeZoneAdjustTime :: (HasCallStack, MonadIO m) => TimeZone -> TimeType -> Int64 -> m (Int32, Int64)
- timeZoneFindInterval :: (HasCallStack, MonadIO m) => TimeZone -> TimeType -> Int64 -> m Int32
- timeZoneGetAbbreviation :: (HasCallStack, MonadIO m) => TimeZone -> Int32 -> m Text
- timeZoneGetIdentifier :: (HasCallStack, MonadIO m) => TimeZone -> m Text
- timeZoneGetOffset :: (HasCallStack, MonadIO m) => TimeZone -> Int32 -> m Int32
- timeZoneIsDst :: (HasCallStack, MonadIO m) => TimeZone -> Int32 -> m Bool
- timeZoneNew :: (HasCallStack, MonadIO m) => Maybe Text -> m TimeZone
- timeZoneNewIdentifier :: (HasCallStack, MonadIO m) => Maybe Text -> m (Maybe TimeZone)
- timeZoneNewLocal :: (HasCallStack, MonadIO m) => m TimeZone
- timeZoneNewOffset :: (HasCallStack, MonadIO m) => Int32 -> m TimeZone
- timeZoneNewUtc :: (HasCallStack, MonadIO m) => m TimeZone
- timeZoneRef :: (HasCallStack, MonadIO m) => TimeZone -> m TimeZone
- timeZoneUnref :: (HasCallStack, MonadIO m) => TimeZone -> m ()
Exported types
Memory-managed wrapper type.
Instances
| Eq TimeZone Source # | |
| GBoxed TimeZone Source # | |
Defined in GI.GLib.Structs.TimeZone | |
| ManagedPtrNewtype TimeZone Source # | |
Defined in GI.GLib.Structs.TimeZone Methods toManagedPtr :: TimeZone -> ManagedPtr TimeZone | |
| TypedObject TimeZone Source # | |
Defined in GI.GLib.Structs.TimeZone | |
| HasParentTypes TimeZone Source # | |
Defined in GI.GLib.Structs.TimeZone | |
| IsGValue (Maybe TimeZone) Source # | Convert |
Defined in GI.GLib.Structs.TimeZone Methods gvalueGType_ :: IO GType gvalueSet_ :: Ptr GValue -> Maybe TimeZone -> IO () gvalueGet_ :: Ptr GValue -> IO (Maybe TimeZone) | |
| type ParentTypes TimeZone Source # | |
Defined in GI.GLib.Structs.TimeZone | |
Methods
Click to display all available methods, including inherited ones
Methods
adjustTime, findInterval, isDst, ref, unref.
Getters
getAbbreviation, getIdentifier, getOffset.
Setters
None.
adjustTime
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> TimeType |
|
| -> Int64 |
|
| -> m (Int32, Int64) | Returns: the interval containing |
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 timeZoneFindInterval, with the
difference that it always succeeds (by making the adjustments
described below).
In any of the cases where timeZoneFindInterval 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.
Since: 2.26
findInterval
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> TimeType |
|
| -> Int64 |
|
| -> m Int32 | Returns: the interval containing |
Finds an interval within tz that corresponds to the given time_.
The meaning of time_ depends on type.
If type is TimeTypeUniversal then this function will always
succeed (since universal time is monotonic and continuous).
Otherwise time_ is treated as local time. The distinction between
TimeTypeStandard and TimeTypeDaylight 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.
Since: 2.26
getAbbreviation
timeZoneGetAbbreviation Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> Int32 |
|
| -> m Text | Returns: the time zone abbreviation, which belongs to |
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.
Since: 2.26
getIdentifier
timeZoneGetIdentifier Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> m Text | Returns: identifier for this timezone |
Get the identifier of this TimeZone, as passed to timeZoneNew.
If the identifier passed at construction time was not recognised, UTC will
be returned. If it was Nothing, 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.
Since: 2.58
getOffset
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> Int32 |
|
| -> m Int32 | Returns: the number of seconds that should be added to UTC to get the
local time in |
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).
Since: 2.26
isDst
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> Int32 |
|
| -> m Bool | Returns: |
Determines if daylight savings time is in effect during a particular
interval of time in the time zone tz.
Since: 2.26
new
Arguments
| :: (HasCallStack, MonadIO m) | |
| => Maybe Text |
|
| -> m TimeZone | Returns: the requested timezone |
Deprecated: (Since version 2.68)Use timeZoneNewIdentifier instead, as it provides error reporting. Change your code to handle a potentially Nothing return value.
A version of timeZoneNewIdentifier 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
timeZoneNewIdentifier.
Since: 2.26
newIdentifier
timeZoneNewIdentifier Source #
Arguments
| :: (HasCallStack, MonadIO m) | |
| => Maybe Text |
|
| -> m (Maybe TimeZone) | Returns: the requested timezone, or |
Creates a TimeZone corresponding to identifier. If identifier cannot be
parsed or loaded, Nothing 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 Nothing).
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).
timeZoneNewLocal 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 Nothing 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 timeZoneUnref
when you are done with it.
Since: 2.68
newLocal
Arguments
| :: (HasCallStack, MonadIO m) | |
| => m TimeZone | Returns: the local 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 timeZoneNew with the value of
the TZ environment variable (including the possibility of Nothing).
You should release the return value by calling timeZoneUnref
when you are done with it.
Since: 2.26
newOffset
Arguments
| :: (HasCallStack, MonadIO m) | |
| => Int32 |
|
| -> m TimeZone | Returns: a timezone at the given offset from UTC, or UTC on failure |
Creates a TimeZone corresponding to the given constant offset from UTC,
in seconds.
This is equivalent to calling timeZoneNew 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
timeZoneNewIdentifier directly.
Since: 2.58
newUtc
Arguments
| :: (HasCallStack, MonadIO m) | |
| => m TimeZone | Returns: the universal timezone |
Creates a TimeZone corresponding to UTC.
This is equivalent to calling timeZoneNew with a value like
"Z", "UTC", "+00", etc.
You should release the return value by calling timeZoneUnref
when you are done with it.
Since: 2.26
ref
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> m TimeZone | Returns: a new reference to |
Increases the reference count on tz.
Since: 2.26
unref
Arguments
| :: (HasCallStack, MonadIO m) | |
| => TimeZone |
|
| -> m () |
Decreases the reference count on tz.
Since: 2.26