IF statement using Time

This is probably really basic but I can't for the life of me get this to work.  I have 2 cells that contain a date and a time, cell a and B.  In order to calculate duration I have added these two cells together and formatted the cells as [h]:mm:ss.  I would now like to calculate the percentage of calls that were made in 15 mins or less.  My formula is =If(c2<0:15:00,1,0).

What am I missing here?
Rrave26Asked:
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byundtMechanical EngineerCommented:
A duration suggests that you have two cells with date/time information and are looking at their difference. To see if it is less than 15 minutes, consider:
=IF(B2-A2<=TIME(0,15,0),1,0)

If the above discussion is not solving your problem, could you please post a sample workbook so the discussion can be specific to your situation?

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byundtMechanical EngineerCommented:
You can calculate the percentage of differences that are 15 minutes or less with a formula like:
=SUMPRODUCT(((B1:B30-A1:A30)<=TIME(0,15,0))*(A1:A30<>0)*(B1:B30<>0))/SUMPRODUCT((A1:A30<>0)*(B1:B30<>0))
Rrave26Author Commented:
That worked perfectly.  Thanks.
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