date_combo_validate in core/modules/date/date.elements.inc

Validate and update a combo element.

date_default_value in core/modules/date/date.elements.inc

The callback for setting a default value for an empty date field.

date_field_load in core/modules/date/date.field.inc

Implements hook_field_load().

date_field_validate in core/modules/date/date.field.inc

Implements hook_field_validate().

date_formatter_process in core/modules/date/date.module

Helper function for creating formatted date arrays from a formatter.

date_prepare_entity in core/modules/date/date.module

Helper function to adapt entity date fields to formatter settings.

date_tokens in core/modules/date/date.tokens.inc

Implements hook_tokens().