jonhunt wrote:

Scoops,

You are right about the plus minutes.

I changed to the 1904, but I still get the num error when we are early
rather than late.

I had already tried the other suggestion of 1440 and that doesn't seem
to work.

I really didn't understand your comment "Note that this will change any
dates that already exist in your sheet
and you will need to amend them." What will I need to amend?

Hi Jon

Not sure why your sheet isn't performing, if I toggle the 1904 date
system, I get the right answer or a cell full of #.

As for the amendments - try typing a date into Excel under the default
1900 and then use 1904. You should see the date shift by 1462 days so,
to see it as it was before the change you'd amend it by the same (i.e.
thedate-1462). Any new dates can be entered "as is".

Regards

Steve