On Fri, Jul 21, 2006 at 02:50:57PM +0200, Srdjan Krajnalic wrote:
Hi,
Unless I'm missing some of the data files, the only rule TYPE ever used is "-"
You can find yearistype.sh in tzdata, which defines what TYPEs are supported. Currently they are: even odd uspres nonpres/nonuspres. The even/odd types were used in South Australia, which used to look like this (snippet taken from tzdata96a.tar.gz): # South Australia # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule AS 1971 1985 - Oct lastSun 2:00s 1:00 - Rule AS 1986 only - Oct 19 2:00s 1:00 - Rule AS 1987 max - Oct lastSun 2:00s 1:00 - Rule AS 1972 only - Feb 27 2:00s 0 - Rule AS 1973 1985 - Mar Sun>=1 2:00s 0 - Rule AS 1986 1989 - Mar Sun>=15 2:00s 0 - Rule AS 1990 1994 even Mar Sun>=18 2:00s 0 - Rule AS 1990 1994 odd Mar Sun>=1 2:00s 0 - Rule AS 1995 max - Mar lastSun 2:00s 0 - The underlying reason for even/odd usage in this rule is that the Adelaide Festival of the Arts is in March of even years since 1960. http://www.adelaidefestival.com.au/ Since there were only 5 years of this even/odd algorithm (and it is not expected to reappear in future), it was decided to just hard code the dates for those 5 years, so that yearistype would not be required for this rule. While the TZ database does not currently use year types, it is always possible that some juridiction in the world will decide to have daylight saving rules which are different every 2 years, or every 4 years, or some other scheme that will require extending yearistype. ___________________________________________________________________________ David Keegel <djk@cybersource.com.au> http://www.cyber.com.au/users/djk/ Cybersource P/L: Linux/Unix Systems Administration Consulting/Contracting