On Mon, 26 May 2008 19:21:17 +0100, "Sandy Mann"
wrote:

Change the sheet date system to the 1904 date system Tools Options
Calculation place a check in the 1904 date system. Just be warned that
this will change all dates by four yeas and one day.

An alternative would be to put 1 positive 1:30 : in D3 and then use:

=IF(SUM(D1:D11)-D3*20,SUM(D1:D11)-D3*2,"")

which will show onlt positive times.


Yes I have it sorted now, never knew about the 1904 date system, many
thanks for your time and trouble

Dent