From: Wally.Wedel@Sun.COM Sent: Wednesday, October 15, 1997 4:52 PM a) Does "wall clock" mean simply take the time as given applying no corrections? Yes; it means local time. E.g. in: Rule US 1967 max - Oct lastSun 2:00 0 S the `2:00' means the transition occurs at 02:00 local time. b) Does "standard" mean apply DST time shift to given time to find true time? Yes. E.g. in: Rule GB-Eire 1972 1980 - Oct Sun>=23 2:00s 0 GMT the `2:00s' means 02:00 local standard time. At those times there happens to be a 1-hour DST shift, so this happens to be equivalent to 03:00 local (daylight) time. c) Does "GMT" mean apply GMT offset to given time to get true time? Yes. E.g. in: Rule EU 1996 max - Oct lastSun 1:00u 0 - the `1:00u' means 01:00 UTC. E.g. for Europe/Helsinki, the change occurs at 04:00 local time, since they are 3 hours ahead of UTC in the summer. 2) Is the convention for rule naming that when searching for the applicable rule, one looks for a rule with the specified name covering the specified date? I assume that failure to find a rule implies no time shift. This sounds correct, but to make sure, perhaps you could clarify your question with an example. 3) The comments in the data files contain quite important information about the actual coded information. Have you considered converting them to HTML to get them better tagged? I'm particularly interested in tagging some kind of a long name usable in reports and like. It'd be nice to have something like that. Have you looked at zone.tab and iso3166.tab, and how tzselect.ksh uses these auxiliary tables? Perhaps this could give you an idea about how to add info and/or generate HTML.