Formate from calendar is not taking over correctly - by: john001

Dear all,

when entering a date via calendar menu, the date will be put in the input box using the formate d.F.Y
Unfortunately the date is not saved when saved at all. Looks like that all date input boxes are affected.
When putting the date manually in the input box using the formate d.m.Y it will be saved.
How that bug can be fixed?

Thanks for your advice in advance!