Here's the table I have

Date         # Days Open
02/01/2008    3
02/01/2008    2
02/05/2008    3
02/11/2008    1
02/11/2008    1
02/12/2008    14
02/15/2008    8
02/18/2008    2
02/18/2008    4
02/20/2008    4
02/21/2008    15
02/22/2008    1
02/26/2008    4
02/27/2008    9
02/27/2008    8
02/29/2008    1
02/29/2008    13

Date is manually input, # days open is calced using networkdays and another
manually input date.

Out of this table, I can count how many items fall within a date range based
using sumproduct.  What I need to be able to do is sum the days that
fallwithin a date range.  For example, the first date range is 02/01/2008 to
02/10/2008.  I know there are 3 items there, but I want to add up the 3, 2,
and 3 for that range.

I have cell references indicating the date range I wish to use.  What would
I add on to this formula to sumup the # days open for the given date range?  
I'm using the formula =SUMPRODUCT((J9:J26>=AM102)*(J9:J26<=AM103)) to
determine the # of items in the date range (date ranges in col AM).  I should
come up with 8 for the date range of 02/01/2008 to 02/10/2008.

Thanks in advance for any help.