Tribe: Change date format on Community Events Add form

functions.php

// NOTE: This won't fully work, as the date format is changed back with javascript
//       once the user selects a date with the date picker.

// Add this to your active theme's functions.php
add_filter( 'tribe_community_events_get_start_date', 'tribe_change_community_events_date_format' );
function tribe_change_community_events_date_format( $date, $event_id ) {
    $date = date( 'y-m-d', strtotime( $date ) ); // change date configuration to desired
    return $date;
}