Excel 2007 Difference between 2 dates showing as a negative number

[KJ2607]

Hi I'm having problems with the following formula:

A		B		C
Date Opened		Date Closed		Total days to closeout
26/07/2013		13/08/2013		18
26/07/2013		19/08/2013		24
31/07/2013				-41486
01/08/2013				-41487

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I want to copy the following formula in Column C all the way down: B2-A2 to work out the total amount of days it takes to close an issue out. However until I get a closure date, the formula shows a negative number - which is throwing off my average calculation at the end - any suggestions?

 

[VoG]

Try

=IF(B2="","",B2-A2)

 

[KJ2607]

Thats Great Thanks VoG!!

If I was also looking to create a separate column to actually count he amount of days an issue was open before it was closed off, I had written the following formula:

=IF(ISBLANK (B2), Today()-A2, B2-A2) Which works well so long as I have a start date, However if I don't have a start date, the cell automatically fills in with some random number? Is there anyway to combine what you posted above with my current formula?

 

[VoG]

Try

=IF(OR(A2="",B2=""),"",IF(ISBLANK(B2), TODAY()-A2, B2-A2))

 

[KJ2607]

Wonderful Thanks again VoG!