Takes a valid date and time and exports it in a format that is compatible with ACF's DateTime field as well as MYSQL's DATETIME type.
See documentation on <timestamp> and on the timestamp parser for more information on supported attributes and valid inputs.
format : 'Y-m-d H:i:s'
<datetime>today 2pm</datetime>
<!-- Exports: '2019-07-24 14:00:00' -->