Frist
The period within which you must act.
A deadline usually starts the day after an event (notification, service, receipt) and ends on a certain day at midnight (§ 187 Abs. 1 BGB, § 188 Abs. 2 BGB). If the end falls on a Saturday, Sunday or public holiday, it ends on the next working day (§ 193 BGB).
How it appears in the letter
»… innerhalb eines Monats nach Bekanntgabe …«