Hi,

Try this with the project number your looking for in C1, change the ranges
to suit your data but they must all be the same size.

=MIN(IF(B1:B20=C1,IF(A1:A20<"",A1:A20)))


This is an array formula which must be entered by pressing CTRL+Shift+Enter
'and not just Enter. If you do it correctly then Excel will put curly brackets
'around the formula {}. You can't type these yourself. If you edit the formula
'you must enter it again with CTRL+Shift+Enter.

Mike

"MCscrewdriver" wrote:

Probably dead easy but its got me stumped.
Each week hours are booked to a number of different projects by 20 or more
people. I need to identify the first date any time was booked to a particular
project.
Column A is the list of dates and column B is the project reference number.
neither of the columns are in order.
once i get this sorted i then need to use different tables of rates
depending on the start date to calculate project costs (but more of that
later)