Credit Card on File Expiration Formula
You can calculate the credit card expiration using the number of days in a month minus the value in the parameter setting. The following example provides the formula for a credit card that expires in December with a parameter setting of 10 days. The application uses the following formula for the application message.
Formula = Number of Days in the Month - Parameter Setting = Date of the application message
- Credit Card Expiration Date = 12/2016
 - Parameter Setting = 10
 - Application message activates on December 21, 2016
 
The credit card expires on the last day of the month or December 31, 2016.