In an account, I clicked on Duplicate of a transaction. I got a small popup with the date field highlighted. I typed in 5.19.21 (instead of the correct 5/19/21) and pressed enter. That got me the transaction duplicated, but with the date of 12/31/1969. Seems like the code should warn me about bad date. I am running GnuCash 4.14 on Linux Fedora 37