create date type in install profile
If you want to use a custom date format, you should write this as a record in the database. In your profile-install function, you can use following code to accomplish this:



system_date_format_save(array(
    'format' =&gt; 'd.m.Y',
    'type' =&gt; 'custom',
    'locked' =&gt; 0,
    'is_new' =&gt; true,
));