Excel and Unix Timestamp manipulation

[sergio_84]

Hi everyone,
I have a "concept" question about how should I use unix timestamp in Excel.
I would like to know what is the correct way of storing an Unix timestamp in a Excel table in terms of GMT,UTC,etc. as well as winter/summer hour difference.

For example if I am in Spain and want to save a Unix Timestamp, should I take into consideration that its +2hours when saving the value in a cell? or +1hours in winter?
Or should I save it in a certain neutral way, and then convert the value when reading it?
this problem has also been killing me in php so a solution will help me for two issues.

Thank you very much for your time.

[FDibbins]

my view would be to save it neutral, that way you can adjust it afterwards to suite whatever your requirements are. If you adjust it up front, 1 way, then decide you need it a different way afterwards, you may need to do 2 conversions...or at least 1, more complex, adjustment