This example illustrates how to use the DATEDIF function to calculate the number of days that have elapsed between the order date and today for purposes of informing the customer.

Source:

For the orders in the following set, you want to charge interest for those ones that are older than 90 days.

Transformation:

The first step is to create a column containing today's (03/03/16) date value:

You can now use this value as the basis for computing the number of elapsed days for each invoice:

The age of each invoice in days is displayed in the new column. Now, you want to add a little bit of information to this comparison. Instead of just calculating the number of days, you could write out the action to undertake. Replace the above with the following:

To be fair to your customers, you might want to issue a notice at 45 days that the invoice is outstanding. You can replace the above with the following:

By using nested instances of the IF function, you can generate multiple results in the TakeAction column.

For the items that are over 90 days old, you want to charge 5% interest. You can do the following:

The above sets the value in the Amount column based on the conditional of whether the TakeAction column value is Charge interest. If so, apply 5% interest to the value in the Amount column.

Results: