This is a configuration option to limit the number of days that you enter in a payment date for Account Receivables. When entering in a date that is outside the setting the user will receive an error to contact their administrator. This should alleviate accidentally posting payments in previous quarters or years.
The MaxDaysPostedDateAR property limits how far back users can posted an AR payment in the system. This helps to prevent entering payments in previous quarters or years.
Config Option > Branch > Branch Setting
Blank (which implies no maximum) or Numeric Value for a number of days.
Example: If the Config Option is set to 15, users will not be able to post a payment for 16+ days back from today's date.