Number of days between dates, leave blank if 0

[Wwach]

So, it's been a really long time since I've had to use formulas, and I am drawing a complete blank. I am needing the formula for the number of days that have passed since I received a time from when I requested the document, and if I have not received the document yet, then the cell needs to be 0. Can I please request assistance?

EX:
Requested - 4/15/15
Received - 6/12/15
Days passed: 58

 

[Joe4]

Welcome to the Board!

Not quite clear if you want to return a zero or blank (your description seems to contradict your title)

Zero:
=IF(B1="",0,B1-A1)

Blank:
=IF(B1="","",B1-A1)

 

[Wwach]

Thank you so much, that worked. And you are correct, I did contradict myself. Sorry!!

 

[Joe4]

No worries!
Glad it worked out for you.