#Amsterdam2019

I've reverted some of the code that removed datetime_wrapper theme hooks and preprocessing and I think we need to add the templates back as well and deprecate that properly.

I added the templates back and added a deprecation.

And I drafted a change record: https://www.drupal.org/node/3530128 →

Has the datetime-local element been considered as replacement for some of these scenarios? If there's a time element, this option is a much better UX to eliminate wrappers. Theres a few related patches that fix a few datetime-local issues.

There are a few browser compatibility issues for datetime-local with safari & firefox not showing the time picker but time can still be entered. Is that a deal breaker?
Internet Explorer doesn't support it all. Do we still care about IE?

For just dates, a custom element that extends Datetime would work that just removes the theme wrappers and replaces the date title with the element title. The only one that should get a fieldset wrapper IMO is the date list widget if we could adopt datetime-local.