Since the non-time portions are day offsets from some starting time, just
subtract 1 from the date and you will have the day before's date...

=IF(AND(B6="",B4<""),NOW()-1,IF(AND(B4<"",B6<""),B6,""))

By the way, if you only need the date, without the time portion, you can use
the TODAY() function in place of the NOW() function.

Rick


"bbc1" wrote in message
...
Hi I am using this formula to return a date when spreadsheet is altered, I
require the date to ne one day less than the present day. Ie is the actual
date is 6/6/08 need it to return the 5/6/08
=IF(AND(B6="",B4<""),NOW(),IF(AND(B4<"",B6<""), B6,""))
any help would be greatly appreaciated.