IF functionality, Logical Test = Nonbalnk Cell

[Guest]

I have a spreadsheet that holds design proiducts that have been or need to
be closed out. I'm looking to count the number of days these taken to close
by subtracting the date opened from the date closed or for the currently open
ones subtracting todays date from the date opened.

For closed item I use: ex "=DAYS360(M2,F2)" (M2 = date opened, F2 = date
closed)
For open items: "=DAYS360(TODAY()-F2)"

I have to use updated data each week for this and would like to streamline
the updating by using and IF function for each count.

My question is how do I cont non-blank cells for a logical test in an IF
function.
Example for closed items:
=IF(M2="*?",M2-F2,""), this returns a blank or whatever I have for the FALSE
return. How do return a TRUE condition for when a date is in cell M@?

Thanks,

-bob

PS..sorry for the long explanation

 

[JE McGimpsey]

One way:

=IF(M2<>"",M2-F2,"")