I have issue with simple formula but do not know why it shows 0 even in the case of F16 more than 0?
Try dates like:
E16 as Start date Nov 03 2009
F16 as End date Nov 09 2009

=IF(AND(F16>0;E16>0);F16-E16)*OR(IF(AND(F16=0;E16=0);0))*OR(IF(AND(F16=0;E16>0);TODAY()-E16))

Separate formula works with exact numbers but OR does not.

Possibilities are the following:
1. both more than 0 and calculation F16-E16
2. both equal 0 and calculation with value 0
3. if F16 is 0 it should calculate delay of payment: TODAY()-E16

Is there issue in calculation as formula does not have an error?