» Indicating Due Payments, Based on the Current Date

Problem:

Column B contains the date of the last payment made by each of the clients listed in column A.
Payments are to be collected from each client every two weeks.
We want to indicate which clients have payments due today, based on the number of days since their last payment.

Solution:

Use the IF, MOD, and TODAY functions as shown in the following formula:
=IF(MOD(TODAY()-B2,14)=0,"Pay Today","")
Thus, the string "Pay Today" will appear next to each client whose payment is due today.