Date: Sat, 14 Mar 87 13:29:55 EST From: elsie!ado (Arthur David Olson) Message-ID: <8703141829.AA01740@elsie.UUCP> Dumb question #1: what applications use the offset from GMT of local time? Anything which wants to record time in local time (for ease of human reading) but be precise about the zone so the precise GMT time can be reconstructed. Mailers are a prime example, the Date: line should contain such an offset (only in the 5 US zones is it allowable to use an abbreviation .. except the stupid US military one letter abbreviations; and even those 5 are only allowed in rfc822 style mail, ISO stuff always requires the numeric offset) Dumb question #2: if there's a way to turn tm structures ... does .. [ being able to deduce it ] ... obviate the need for a GMT offset element in the tm structure? Certainly, this is possible. Initially I wasn't realy impressed with the need for the offset in the struct tm because of how easy it is to obtain this way (even without the inverse functions, its not hard to do a struct subtraction (ie: multiple subtractions, with additions & multiplications to combine the answers) of the results of gmtime() and localtime()). But the zone offset information is trivially available to localtime, it seems like it can't hurt to provide this extra information, essentially for free. kre