Date under name should be last reply time. But it updated when next time visit the page after send a reply.
Date format come from your settings in Dashboard > Settings > General.
If you want to show “x ago” Then add following code in your theme’s (child theme’s if you are using) functions.php

add_filter( 'fep_formate_date', function( $h_time, $date ){
    return sprintf( __( '%s ago', 'front-end-pm' ), human_time_diff( strtotime( $date ) ) );
}, 10, 2);