Conditional PRODUCT function formula

Hi,

I am trying to use a PRODUCT formula to return the product of a list of numbers in a column, between 2 specified dates. The spreadsheet is arranged as follows:

Column B A list of dates
Column C & D Numerical data not used in any calculations
Column E The numbers to multiply together
Cell A1 Start date to be used in the PRODUCTformula
Cell A2 End date to be used in the PRODUCT formula

The formula I have to multiply the data in column E, subject to the start and end dates in Column A is:

{=PRODUCT(IF(B15:B1000>A1,IF(B15:B1000<=A2,INDEX(B15:E1000,0,4))))}

This returns zero though works appropriately if I replace “PRODUCT” with a “SUM”.

Can someone please suggest what I’m doing wrong?

Thanks!