Field help (ENDMONFLG) 

The three values for this field are:


The flag is not taken into account.

End of next month:

The due date calculated after applying the number of months and days is postponed until a month end (ex: 45 days and on month end).

End of current month:

The due date start is postponed up to the end of month first and then the additional number of months and days are applied to determine the final due date (ex: End of month and 45 days).