Hi, I am a Delphi programmer and am working on a time zone problem. In the Olson database I'm having trouble differentiating between times that are strictly standard and those that include summer time / daylight savings. Is there a standard in the code for differentiating these? Most of it is fairly simple to understand but I am mystified by some of the abbreviations in the rule changes. For instance: # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Finland 1942 only - Apr 3 0:00 1:00 S Rule Finland 1942 only - Oct 3 0:00 0 - Rule Finland 1981 1982 - Mar lastSun 2:00 1:00 S Rule Finland 1981 1982 - Sep lastSun 3:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Helsinki 1:39:52 - LMT 1878 May 31 1:39:52 - HMT 1921 May # Helsinki Mean Time 2:00 Finland EE%sT 1983 2:00 EU EE%sT What is the % symbol I keep seeing in the code for? For instance, in "2:00 EU EE%sT" is "EE%sT" Eastern European Standard Time? I take this to mean that Finland is currently on EU rules with a UTC offset of +2. Every now and then I also find something like this: "2:00 1:00 EEST 1989 Sep 24 2:00s" Does this line mean that I add 1 hour to the 2:00 hours UTC? Or is this correction already included in the 2 hours? Thanks! Sincerely, Curtis Manwaring