Eliminating Negative Values from Date Subtractions

Thanks for this formula it works great for counting past days of the current date. The only problem is that you get a 39015 value for any blank cells... How is this fixed? Thanks In Advance

Problem:

Creating a formula to return the number of days between each date in column A and the corresponding deadline in column B.
In cases where the date in column A is later than the deadline, the formula is to return zero rather than a negative number of days.

Solution:

Use the MAX function as shown in the following formula:
=MAX(B2-A2,0)