Issue #1396536, Repeating fields weren't getting created with Devel Generate because of the change in widgets. Add new hooks so Date Repeat Field can add the repeats.

Issue #874322, The All Day functionality has been moved into a separate module and hooks were added to make it easier for other modules to inject steps into date processing.

 Issue #1363460, Make sure widget dates do not end up with the current date when they should be empty.

The repeat description was lost by a recent change to the theme that sent the element through the theme twice.

Issue #1338194, Logic for creating end date wasn't taking into account the possibility that a field might have no value2.

Issue #1216878, Re-introduce 'repeat' as a field setting rather than a widget type so people can't try to switch back and forth between repeating and non-repeating dates. Eliminate repeat widgets.

Issue #1234140 by arlinsundbulte, Change terminology in user-facing text from 'From/To Date' to 'Start/End Date'.

Fix some code that was still using the colon separator in the date id when everything else is now using a period.

Get rid of overlapping formatter functionality. There should be a default formatter with the option to choose a date format as a setting, not a formatter for each format. This was a leftover from the D6 functionality.

#1021512 Fields on user that don't show up on registration form still run through hook_field_validate. Don't validate missing values.

Trying to figure out how to get the list of date fields back into the date argument and filter. Something must have changed.