Store the locale format in a static cache to avoid re-computing it dozens of times on calendar views.

Issue #874322, Add back the date_field_all_day() function to avoid breaking other modules that are using it.

Issue #1236216, Start the process of moving the repeating date integration out of the Date module and into a separate, Date Repeat Field module.

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 #1217796, Make sure that All Day formatting works correctly even if the All Day label is empty.

Issue #1302374 by miro_dietiker, Account for an inconsistency in core handling of non-existant date formats.

Issue #1292898, Check for all day checkbox in the basic date element validation so empty time for newly added elements still passes validation.

Issue #1153766, Adapt metadata functions to the pattern in the current Entity code, add  to the getters.

Issue #1179716, Remove value_callback for date_repeat and date_combo forms, the default behavior works fine.

Issue #1257830, Beef up the logic when creating the date repeat tabs to work for more kinds of entities.

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 #1249724 by KarenS, Gábor Hojtsy, David_Rothstein, Improve usability of date and time input configuration.

Issue #1251592 by David_Rothstein, Set reasonable default values if date formats have not been configured, and add tests for that.

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

Issue #1229362, Date Popup module needs date_is_date() function, which should not require Date module. Move that to Date API.

More work on cleaning up validation, add in some ideas from fearlsgrove about checking the granularity of the input array against the expected granularity.