> Not all days have 24 hours! In particular, days affected by Daylight > Savings Time (in the US, that's usually the first Sunday in April and > last Sunday in October) will have 23 or 25 hours. The first and last time I wrote something like this, someone crossforwarded the thing to i don't know how many people saying "hey, this is a cool joke" and then thanked me for the good laugh. Which should make it obvious: never, ever talk about advanced date calculation in public. This said, never, ever write your own time-handling routines if you can pick a carefully-studied standard library portion that already does that. (or just write a wrapper around the latter) > Might it be simpler to use the platform's mktime() function to > avoid these issues? (I believe that's a Posix-ism). This seems to be the right choice. Mathieu Bouchard