Change hour format

I want to change the hour format from 12-hour to 24-hour.

I´ve found this code:

function gde_24hour_times( $times ) {
	foreach($times as $key=>$val){
		$times[$key]=$key;
	}
    return $times;
}
add_filter( 'geodir_event_schedule_times', 'gde_24hour_times' );

but only change the format in the submit event page.

How can get the change into listings and detail pages?