>>Thinking about this a little more, it's not a trivial problem. You'd need to test if VFP does any compensation already at the time changes.
>
>It doesn't. Let's assume the time of your message and a week before that. That should be 7*24+1=169 hours, because we've had the time moved (actually on my machine it was moved manually - because of the bug Windows once had, I've dropped the automatics):
>

x=DATETIME(2007,11,8,14,14,12)
>x8=DATETIME(2007,11, 1, 13,45,56)
>?x8-x
>?x-x8
>SET DECIMALS TO 13
>?(x-x8)/(24*3600)
>

>
>The only adjustment I suspect VFP makes is usage of seconds() over midnight - it was changed at some point to continue counting and not reset to zero. Not sure when does it actually reset - there's zero mention of any change in the Help.

Please pardon me for jumping in. First of all, isn't this really a storm in a teacup? And when you turn the clock backward in the autumn, you actually have the same time twice. How do you specify whether it's 02:30 the first time, or 02:30 the second time?

I remember an interview with an train conductor a few years ago about DST.
Reporter: You have very strict time tables, what do you do when you turn the clock backward?
Conductor: We park the train for an hour at the last station just before 03:00.
Reporter: And in the spring when you set the clock forward?
Conductor: We have to drive as fast as heck to make up for the missing hour. :-)

NB! In Norway we are expected to wake up at 03:00 , set the clock backward to 2:30, and go back to sleep. I guess it's the same "over there"?