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glibmm 2.80.0
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TimeZone - A structure representing a time zone. More...
#include <glibmm/timezone.h>
Public Member Functions | |
| TimeZone () | |
| TimeZone (GTimeZone *gobject, bool make_a_copy=true) | |
| TimeZone (const TimeZone &other) | |
| TimeZone & | operator= (const TimeZone &other) |
| TimeZone (TimeZone &&other) noexcept | |
| TimeZone & | operator= (TimeZone &&other) noexcept |
| ~TimeZone () noexcept | |
| void | swap (TimeZone &other) noexcept |
| GTimeZone * | gobj () |
| Provides access to the underlying C instance. | |
| const GTimeZone * | gobj () const |
| Provides access to the underlying C instance. | |
| GTimeZone * | gobj_copy () const |
| Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs. | |
| operator bool () const | |
| Returns true if the TimeZone object is valid. | |
| int | find_interval (TimeType type, gint64 time) const |
| Finds an interval within tz that corresponds to the given time. | |
| int | adjust_time (TimeType type, gint64 & time) const |
| Finds an interval within tz that corresponds to the given time, possibly adjusting time if required to fit into an interval. | |
| Glib::ustring | get_abbreviation (int interval) const |
| Determines the time zone abbreviation to be used during a particular interval of time in the time zone tz. | |
| gint32 | get_offset (int interval) const |
| Determines the offset to UTC in effect during a particular interval of time in the time zone tz. | |
| bool | is_dst (int interval) const |
| Determines if daylight savings time is in effect during a particular interval of time in the time zone tz. | |
| Glib::ustring | get_identifier () const |
| Get the identifier of this TimeZone, as passed to g_time_zone_new(). | |
Static Public Member Functions | |
| static GType | get_type () |
| Get the GType for this class, for use with the underlying GObject type system. | |
| static TimeZone | create (const Glib::ustring &identifier) |
| A version of g_time_zone_new_identifier() which returns the UTC time zone if identifier could not be parsed or loaded. | |
| static TimeZone | create_identifier (const Glib::ustring &identifier) |
| Creates a TimeZone corresponding to identifier. | |
| static TimeZone | create_local () |
| Creates a TimeZone corresponding to local time. | |
| static TimeZone | create_utc () |
| Creates a TimeZone corresponding to UTC. | |
Protected Attributes | |
| GTimeZone * | gobject_ |
Related Symbols | |
(Note that these are not member symbols.) | |
| void | swap (TimeZone &lhs, TimeZone &rhs) noexcept |
| Glib::TimeZone | wrap (GTimeZone *object, bool take_copy=false) |
| A Glib::wrap() method for this object. | |
TimeZone - A structure representing a time zone.
TimeZone is a structure that represents a time zone, at no particular point in time. It is immutable.
A time zone contains a number of intervals. Each interval has an abbreviation to describe it, an offet 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.
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.
| Glib::TimeZone::TimeZone | ( | ) |
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noexcept |
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noexcept |
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.
| type | The TimeType of time. |
| time | A pointer to a number of seconds since January 1, 1970. |
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static |
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().
Deprecated: 2.68: Use g_time_zone_new_identifier() instead, as it provides error reporting. Change your code to handle a potentially nullptr return value.
| identifier | A timezone identifier. |
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static |
Creates a TimeZone corresponding to identifier.
If identifier cannot be parsed or loaded, nullptr 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 nullptr).
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 nullptr 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.
| identifier | A timezone identifier. |
nullptr on failure. 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 g_time_zone_new() with the value of the TZ environment variable (including the possibility of nullptr).
You should release the return value by calling g_time_zone_unref() when you are done with it.
Creates a TimeZone 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.
Finds an interval within tz that corresponds to the given time.
The meaning of time depends on type.
If type is Glib::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 Glib::TimeType::STANDARD and Glib::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.
| type | The TimeType of time. |
| time | A number of seconds since January 1, 1970. |
| Glib::ustring Glib::TimeZone::get_abbreviation | ( | int | interval | ) | const |
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.
| interval | An interval within the timezone. |
| Glib::ustring Glib::TimeZone::get_identifier | ( | ) | const |
Get the identifier of this TimeZone, as passed to g_time_zone_new().
If the identifier passed at construction time was not recognised, UTC will be returned. If it was nullptr, 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.
| gint32 Glib::TimeZone::get_offset | ( | int | interval | ) | const |
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).
| interval | An interval within the timezone. |
Get the GType for this class, for use with the underlying GObject type system.
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inline |
Provides access to the underlying C instance.
Provides access to the underlying C instance.
| GTimeZone * Glib::TimeZone::gobj_copy | ( | ) | const |
Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs.
| bool Glib::TimeZone::is_dst | ( | int | interval | ) | const |
Determines if daylight savings time is in effect during a particular interval of time in the time zone tz.
| interval | An interval within the timezone. |
true if daylight savings time is in effect.
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explicit |
Returns true if the TimeZone object is valid.
This will return false, for instance, if create_identifier() has been called with an identifier that cannot be parsed or loaded.
| lhs | The left-hand side |
| rhs | The right-hand side |
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related |
A Glib::wrap() method for this object.
| object | The C instance. |
| take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref. |
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protected |
1.9.8