I have a sumproduct formula that I am using to determine the sum between two date ranges and I am getting a Value error.

Example:
SUMPRODUCT(('FY 2006'!A8:A550="12-26-05")*('FY 2006'!A8:A550<="1-1-06")*('FY 2006'!B8:B550))

The problem is that column B containes both text and numbers.

How do I amend the formula to ignore the text (or count as zero)?

Thanks