Quote Originally Posted by Ron Coderre View Post
If you want to test for all 3 conditions, please post everything you've already got working on your DV. Then we can try to squeeze in the missing part.
The blank condition is handled by checking the "ignore blank" box in the "Settings" area on the Data Validation window.
The number range, 0 to 24, is handled by "=AND(I8>=0, I8<25)."