How to amend time format of comments, using child-theme?

Question

How to amend (override) the time format of the comments (of the posts and pages), not touching the wordpress initial installation? I use a child theme and if it is possible in any way to do it from the child theme to prevent my changes been overwritten by the next WP update. I would prefer to use add_filter()

I am trying to use:

// define the get_comment_time callback 
function filter_get_comment_time( $date, $d, $gmt, $translate, $comment ) { 
    $d = "g:i:s";
    return $d; 
}; 

// add the filter 
add_filter( 'get_comment_time', 'filter_get_comment_time', 10, 5); 

But it returns only the string "g:i:s".

WP 4.9.4

Answer 1

You have to return the formatted date string, the following will work:

// define the get_comment_time callback 
function filter_get_comment_time( $date, $d, $gmt, $translate, $comment ) { 
  $d = "g:i:s";
  $date = mysql2date($d, $date, $translate);
  return $date;
}; 

// add the filter 
add_filter( 'get_comment_time', 'filter_get_comment_time', 10, 5);