Brian Candler wrote on 1997-03-30 20:31 UTC:

... Zone Etc/GMT-6 6 - GMT-6 ... Zone Etc/GMT+6 -6 - GMT+6

It appears that the zone offsets in column 3 have the wrong sign - can you check if this is the case?

As usual, if two different conventions are possible, they are both used in various situations. Ok, here is the story again: In the Unix/POSIX world, timezones east of the prime meridian have a negative offset and those west of Greenwich have a positive offset. This gives the U.S. positive values and Russia negative values, which might have seemed reasonable to the U.S. developers in the 1970s ... ;-) In the Internet and ISO standards (RFC 822, ISO 8601, etc.), it is exactly the other way round: east of Greenwich is a positive offset (as these timezones are "ahead of universal time", and west of Greenwich time zones are denoted by a negative offset ("behind UTC"). See also <http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html>. Many people think, the ISO/Internet convention is more intuitive, but the POSIX standard (TZ syntax) had to be compatible to existing Unix practice. Therefore, you'll find different signs at different locations. The third column uses the Internet/ISO convention, the GMT names use the old Unix convention for strange backward compatibility reasons. May be, this should be changed, and these entries should be called UTC instead of GMT anyway today. Anyway, there should normally never be a need to use the GMT entries in the Olson timezone package, as there should be an entry for all locations, and you definitely should use the entry describing your location in order to get correct automatic DST switches. Where are you located? Time zone entries are named after the largest populated area in a time zone, e.g. America/Denver for U.S. Mountain Time (now = UTC-06:00 during the summer). Use this entry if possible instead of the GMT entries, which were only intended as an emergency fallback. To test whether your time is set correctly, use both "date" (show local time) and "date -u" (show universal time). Markus -- Markus G. Kuhn, Computer Science grad student, Purdue University, Indiana, USA -- email: kuhn@cs.purdue.edu