If I understand you correctly and assuming that you have - say - sunset in
B2 and sunrise in C2 the:

=MOD(C2-B2,1)

will give you the hours of darkness.

--
HTH

Sandy
In Perth, the ancient capital of Scotland
and the crowning place of kings


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"joe1999" wrote in message
...
Hi all,

I have a logbook spreadsheet with hours logged in time format and the
total
calculated in the third column formatted [h],mm, If I specify sunset in a
time format can I get the night hours in a seperate column?
cheers