This is the way the original Olson data is set up, and ICU reproduces the Olson data faithfully. In fact, their sign is inverted since the the Etc zones follow the POSIX sign conventions. You might notice that zones such as Etc/GMT+1 appear to have the wrong sign for their GMT offset. The reason for this is that ICU locates zones using a binary search, and the binary search relies on this sort order. This is the same order in which the zones are stored internally, and the same order in which they are returned by TimeZone::getAvailableIDs(). The zones are listed in binary sort order (that is, ‘A’ through ‘Z’ come before ‘a’ through ‘z’). For the most current list of ICU system zones, use the method TimeZone::getAvailableIDs().
Since this list changes one or more times a year, this document only represents a snapshot. This document lists the system time zones, both in order of GMT offset and in alphabetical order of ID. However, it is more typical for users to use a pre-existing system time zone since these represent all current international time zones in use. Users can construct their own time zone objects by specifying the above information to the C++ API. In the C API, time zones are designated by their ID strings. ICU supports local time zones through the classes TimeZone and SimpleTimeZone in the C++ API. The amount by which the GMT offset changes when DST is in effect. In the first half of the year it’s in the southern hemisphere, and in the second half of the year it’s in the northern hemisphere. The precise date and time during the year when DST ends. In the first half of the year it’s in the northern hemisphere, and in the second half of the year it’s in the southern hemisphere. The precise date and time during the year when DST begins. If DST is observed, then three additional pieces of information are needed:
#Between two worlds i.c.u. plus#
Offsets range from approximately minus half a day to plus half a day.
Some IDs consist of three or four uppercase letters these are legacy zone names that are aliases to standard zone names.Īn offset from GMT, either positive or negative. The city chosen is not the only city in which the zone applies, but rather a representative city for the region. It typically has the format continent / city. This consists only of invariant characters (see the file utypes.h). Thus, a time zone is described by the following information:Īn identifying string, or ID. If DST is in use, then specific rules define the point at which the offset changes and the amount by which it changes. Typically, regions closer to the equator do not use DST. The offset might vary throughout the year, if daylight savings time (DST) is used, or might be the same all year long. This site uses Just the Docs, a documentation theme for Jekyll.Ī time zone represents an offset applied to Greenwich Mean Time (GMT) to obtain local time. Updating MeasureUnit with new CLDR data.
0 kommentar(er)
