How to change the “at” word next to the time in the post comments section?

Hi,
How can i change the “at” word next to the time in the post comments section? I want to translate it to “um”.

Sample: 24. OKTOBER 2014 at 21:02 h

I just reviewing the SP forums post and got this request. Immediately I checked the Genesis Comments Callback function and there have no filter for this. Then I paused my mind for few minutes and trying to find a logic for it. Therefore I wrote this code in functions.php file and code is working perfectly:

add_filter( 'gettext', 'theme_change_comment_field_names', 20, 3 );
function theme_change_comment_field_names( $translated_text, $text, $domain ) {

    if ( is_singular() ) {

        switch ( $translated_text ) {

            case 'at' :

                $translated_text = __( 'um', 'genesis' );
                break;
        }

    }

    return $translated_text;
}