>>>Suppose datetime1 has been stored in summertime and datetime2 12 REAL hours later in wintertime. Are you implying that your calculation shows 12 hours difference?
>>
>>No, I'm implying that the calculation shows 35 hours while it should have been 36 hrs.
>
>I think Dragan has the right idea, if you convert your inputs to UTC everything should be OK.
>
>On a quick search I don't see any VFP functions that would help with that, nor anything in Downloads etc. here. Maybe some Win32API functions and some elbow grease could do it: http://news2news.com/vfp/?group=76
>
>On the Wiki: http://fox.wikis.com/wc.dll?Wiki~XMLDateTime~VFP

There's a bunch of functions (API wrappers mostly) written by George Tasker which handle this - download #9738.