Hi,

with the eralier date/time in A1 and the later in b1 try

=B1-A1

Format the cell as [hh]:mm

Mike

"Igor" wrote:

I need a formula to calculate number of hours between data and time set in
the cell by function NOW() and a set date in the same format:

Example:

NOW() - return 29/07/2009 16:06:00
set date - 07/08/2009 06:00:00
result to be difference between the dates presented in hours