Editing the formatting.php file vs functions.php file?

Question

I'd like to format the time-ago date format from 5 min to 5m. I can edit the formatting.php file and make the edit but should I? Should I instead declare the edit in the functions.php file?

From the formatting.php file:

function human_time_diff( $from, $to = '' ) {
    if ( empty( $to ) ) {
        $to = time();
    }

    $diff = (int) abs( $to - $from );

    if ( $diff < HOUR_IN_SECONDS ) {
        $mins = round( $diff / MINUTE_IN_SECONDS );
        if ( $mins <= 1 )
            $mins = 1;
        /* translators: Time difference between two dates, in minutes (min=minute). 1: Number of minutes */
        $since = sprintf( _n( '%s min', '%s min', $mins ), $mins );
    }

As you can see in the last time, I can change '%s min' to '%sm' which does the trick. If WordPress discourages editing the formatting.php file, how would I make this edit in functions.php?

Answer 1

The human_time_diff function applies a filter to the results at the end of the function call.

return apply_filters( 'human_time_diff', $since, $diff, $from, $to );

So, use that filter to replace the text with what you want it to be instead.

https://codex.wordpress.org/Plugin_API#Filters