Hi @Simon,
I’m sorry for the trouble here.
There is unfortunately no way to revert to the previously-implemented time pickers or date pickers. The only thing you could do to achieve this would be to literally uninstall the current versions of The Events Calendar and its add-ons, and then replace them with older versions of the plugins that have the date-pickers you prefer.
Please note, however, that we would not be able to provide support for non-current versions of our plugins. If issues arise and you return to the forums for assistance, the first step will be to get up-to-date with the most recent versions of our plugins.
I hope this information helps!
Thanks,
George