My credit card bill is due 3 weeks after the statement date. The statement date is always the 20th of the month. Due to the variable lengths of months, the due date is not always on the same day.
I'd like to have a TODO item with a time stamp on the credit card bill's due date. How can I do this in org? I know that I could enter 12 different entries for a year. I'm after a single TODO entry with a +1m indicating to roll the rule over to the next month, every month.