wacko@laplace.snu.ac.kr
)rfm@gnu.org
)Version: 1.62
Date: 2004/05/21 15:39:02
Copyright: (C) 1997-2002 Free Software Foundation, Inc.
- Declared in:
- Foundation/NSTimeZone.h
Standards:
- MacOS-X
- OpenStep
- GNUstep
The local time zone can be specified by:
1) the
user defaults database: NSGlobalDomain "Local Time
Zone"
2) the GNUSTEP_TZ environment variable
3) the file "localtime" in
System/Library/Libraries/Resources/NSTimeZone
4) the TZ environment variable
5)
tzset and tznam on platforms which have it
6)
Windows registry, on Win32 systems
7) or the
fallback time zone (which is UTC)
with the
ones listed first having precedence.
If the GNUstep time zone datafiles become too out of date, one can download an updated database from ftp://elsie.nci.nih.gov/pub/ and compile it as specified in the README file in the NSTimeZones directory.
Time zone names in NSDates should be GMT, MET etc. not Europe/Berlin, America/Washington etc.
The problem with this is that various time zones may use the same abbreviation (e.g. Australia/Brisbane and America/New_York both use EST), and some time zones may have different rules for daylight saving time even if the abbreviation and offsets from UTC are the same.
The problems with depending on the OS for providing time zone info are that some methods for the NSTimeZone classes might be difficult to implement, and also that time zone names may vary wildly between OSes (this could be a big problem when archiving is used between different systems).
On platforms where the zone info files are already installed elsewhere it is sufficient to use a symlink provided the GMT+/- zones are added.
Win32: Time zone names read from the registry are different from other GNUstep installations. Be careful when moving data between platforms in this case.
Method summary
DEPRICATED.
Returns an abbreviation to time zone map which is quite large.
Return the default time zone for this process.
Return a proxy to the default time zone for this process.
Destroy the system time zone so that it will be recreated next time it is used.
Set the default time zone to be used for this process.
Returns the current system time zone for the process.
Returns an array of all the known regions.
There are 24 elements, of course, one for each time
zone. Each element contains an array of NSStrings
which are the region names.
Return a timezone for the specified offset from GMT.
The timezone returned does not use
daylight savings time. The actual timezone
returned has an offset rounded to the nearest
minute.
Time zones with an offset of more
than +/- 18 hours are disallowed, and nil
is returned.
Returns a timezone for the specified abbrevition.
The same abbreviations are used in different regions so
this isn't particularly useful.
Calls
NSTimeZone-abbreviation dictionary
an so uses a lot of memory.
Returns a timezone for the specified name.
Returns a timezone for aTimeZoneName, created from the supplied time zone data. Data must be in TZ format as per the Olson database.
Returns the abbreviation for this timezone now. Invokes -abbreviationForDate:
Returns the abbreviation for this timezone at aDate. This may differ depending on whether daylight savings time is in effect or not.
Returns the data with which the receiver was initialised.
Initialise a timezone with the supplied name. May return a cached timezone object rather than the newly created one.
Initialises a time zone object using the
supplied data object.
This
method is intended for internal use by the
NSTimeZone class cluster. Don't use it... use
-initWithName:
instead.
Returns a boolean indicating whether daylight savings time is in effect now. Invokes -isDaylightSavingTimeForDate:
Returns a boolean indicating whether daylight savings time is in effect for this time zone at aDate.
Returns TRUE if the time zones have the same name.
Returns the name of the timezone
Returns the number of seconds by which the receiver
differs from Greenwich Mean Time at the current
date and time.
Invokes
-secondsFromGMTForDate:
Returns the number of seconds by which the receiver
differs from Greenwich Mean Time at the date
aDate.
If the time zone uses
dayl;ight savings time, the returned value will
vary at different times of year.
DEPRICATED: see NSTimeZoneDetail
DEPRICATED: see NSTimeZoneDetail
Returns the name of this timezone.
- Declared in:
- Foundation/NSTimeZone.h
Standards:
- OpenStep
- NotMacOS-X
- GNUstep
This class serves no useful purpose in GNUstep, and is provided solely for backward compatibility with the OpenStep spec. It is missing entirely from MacOS-X.
Method summaryDEPRICATED: Class is no longer used.
DEPRICATED: Class is no longer used.
DEPRICATED: Class is no longer used.