The coding guidelines need updating to reflect that we are now using flatpickr instead of jQueryUI Datepicker. Wiki link: https://wiki.koha-community.org/wiki/Coding_Guidelines
Discussed at the Development IRC meeting on 28 September 2022: https://meetings.koha-community.org/2022/development_irc_meeting_28_september_2022.2022-09-28-21.08.log.html#l-194
*** Bug 31741 has been marked as a duplicate of this bug. ***
Discussed at the Development IRC meeting on 12 October 2022: https://meetings.koha-community.org/2022/development_irc_meeting_12_october_2022.2022-10-12-14.01.log.html#l-255 Message sent to mailing list asking for volunteers to update: https://lists.koha-community.org/pipermail/koha-devel/2022-October/047346.html
I am not sure I could do a good job here, all I know is that you stick a different class on things now... Owen, could you help maybe? https://wiki.koha-community.org/wiki/Coding_Guidelines#jQueryUI_Datepicker