date_date_views_fields in core/modules/date/date.module
Implements hook_date_views_fields().
date_sql_handler::sql_field in core/modules/date/views/
Helper function to create cross-database SQL dates.
date_type_format in core/includes/
Helper function for getting the format string for a date type.
date_views_argument_handler_simple::init in core/modules/date/views/
Get granularity.
date_views_filter_handler_simple::init in core/modules/date/views/
Provide some extra help to get the operator/value easier to use.
_date_views_fields in core/modules/date/views/
Identify all potential date/timestamp fields.