Tim,

See http://www.cpearson.com/excel/LocalAndGMTTimes.htm and
http://www.cpearson.com/excel/datedif.htm .

Download the files from the LocalAndGMTimes page.


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com
(email address is on the web site)

"Tim" wrote in message
...
I would appreciate someone explaining to me how to arrange for Excel to
arrive at correct time differences where two dates and times from a year
long
list have been chosen, each of these time points being expressed using
different time zones. This will occur in any simple list of dates and
times
covering a year where one chosen time point is during a period of Standard
Time and another to be compared is during Daylight Savings Time.
Regards,
--
Tim