the rules are not trivial, see https://github.com/eggert/tz/blob/master/asia#L1000 however, it would still be very useful on embedded devices to at least support correct summer/winter-time switching starting from the present.
See http://uclibc.org/FAQ#timezones
I'm aware of the TZ variable format. However, this doesn't allow one to refer to "the Friday before the last Sunday in March" and not at all to "the first Sunday after October 1. If the end of IDT falls on Rosh Hashanah, the Jewish New Year, then IDT will end on the first Monday after October 1". (from https://en.wikipedia.org/wiki/Israel_Summer_Time ) Obviously, it is possible to include rules for a specific year by just refering to the exact days. This would be sufficient if there was a method to define rules for more than just the current year. This could be achieved by extending the TZ variable gramar from std offset dst offset, rule into std offset dst offset, rule[@year[, rule@year][, ...]]
(In reply to comment #2) > I'm aware of the TZ variable format. However, this doesn't allow one to refer > to "the Friday before the last Sunday in March" and not at all to "the first > Sunday after October 1. If the end of IDT falls on Rosh Hashanah, the Jewish > New Year, then IDT will end on the first Monday after October 1". (from > https://en.wikipedia.org/wiki/Israel_Summer_Time ) > > Obviously, it is possible to include rules for a specific year by just refering > to the exact days. This would be sufficient if there was a method to define > rules for more than just the current year. > This could be achieved by extending the TZ variable gramar from > std offset dst offset, rule > into > std offset dst offset, rule[@year[, rule@year][, ...]] As said, see http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03 the TZ variable. If that does not work for you then you will have to fix it there first. thanks,
I filed this issue to be fixed in the upstream standard http://www.austingroupbugs.net/view.php?id=661