sumif criteria using date

[crapit]

Hi,
How to put in the criteria if I want to sum Column 'B' if month in
column 'A' doesn't exceed MAR-2011

A B
Aug-2010 300.00
Sep-2010 300.00
Oct-2010 300.00
Nov-2010 300.00
Dec-2010 300.00
Jan-2011 300.00
Feb-2011 2000.00
Mar-2011 400.00
Apr-2011 400.00
May-2011 400.00
Jun-2011 400.00
Jul-2011 400.00

 

[Dave Peterson]

If those values in column A are real dates:

=sumif(a:a,"<"&date(2011,4,1),b:b)

 

[crapit]

never mind I got it