If you want to sum based on a date range:

b13 = lower boundary date
b14 = upper boundary date

=SUMIF(a20:a1000,"="&b13,c20:c1000)-SUMIF(a20:a1000,"=<"&b14,c20:c1000)

Note that the boundary dates are included in the sum.
Format as General or Number

Credit to: --
Biff
Microsoft Excel MVP


"Ron0210" wrote:

How do you write a sumif formula using a range for the criteria. For example:
=sumif(a20:a1000,b13:b14,c20:c1000) which does not seem to work. My
spreadsheet has a series of dates in column a with corresponding values
column c and I want to sum column c for a particular range of dates defined
by b13 and b14. A typical range would be a month. My spreadsheet will have
dates and values and I want to determine sums for certain months.