If you only would want to pick up Jan-values of a certain year (say,
2004) and B2:B13 houses true dates...

In D2 enter: 1-Jan-2004

In E2 enter:

=DATE(YEAR(D2),MONTH(D2)+1,0)

then invoke:

=SUMIF(B2:B13,"="&D2,C2:C13)-SUMIF(B2:B13,""&E2,C2:C13)

a921 wrote:
I'm looking to use the "sumif" formula listed above.
However my data lists Jan-03 and Jan-04. How do I account
for the years in the above formula? Thanks in advance!!