=SUMPRODUCT(--(Sheet1!$A$1:$A$10<=A1),--(Sheet1!$B$1:$B$10=A1))

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HTH

Bob

"Bernie" wrote in message
...
I have a start and end date on one sheet, another sheet with a list of
dates
in the month.
I need to know how many instances the item was active on a given date
such as
1/1/09 - 5
1/3/09 - 4
1/6/09 - 1
Start End
1/1/2009 1/2/2009
1/1/2009 1/3/2009
1/1/2009 1/6/2009
1/1/2009 1/5/2009
1/1/2009 1/3/2009

Thanks Bernie