"ForSale" wrote in
message ...

I have on sheet1 a couple thousand rows of data. A:A contains dates,
B:B contains ID numbers.
on sheet2 I need to know how many instances an ID number shows up on a
selected date. The specified ID number will be in sheet2, A2; the
specified date will be in sheet2, A1. It seems like I want a Countif,
but it only allows for one criteria as far as I know. What kind of
formula do I need for this?
Thanks.


Please have a look at array formulas
(http://www.cpearson.com/excel/array.htm)
This technique allows you to SUM all instances, where an ID number matches a
given date.

Joerg