Membership plan (calendar time limit not working)

The membership plan cannot be set so that it is limited until the end of the year?! I can only set the length for 1 year, but the function field below (with the calendar selection field) can be entered, but is deleted again when saving and does not work either (if I click on renew for a pending member, 1 year from today's date is always calculated as the annual period but not 31.Dec.2025)? Is there a bugfix available?