=SUMPRODUCT(--(TEXT(A2:A25,"yyyymmm")="2005Jan"),D2:D25)

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HTH

Bob Phillips

"Excel date range function" <Excel date range
wrote in message
...
I have created the function SUMIF(A2:A25,"1/10/05",D2:D25) where the
entries
of the A column are dates and the D column are amounts. For every entry
on
1/10/05, it totals the amount. How can I apply this function with a date
range criteria of one month instead of just one day?