function genesis_human_time_diff( $older_date, $newer_date = false, $relative_depth = 2 ) {

  if ( ! is_int( $older_date ) ) {
    return '';
  }

  // If no newer date is given, assume now.
  $newer_date = $newer_date ?: time();

  // Difference in seconds.
  $since = absint( $newer_date - $older_date );

  if ( ! $since ) {
    return '0 ' . _x( 'seconds', 'time difference', 'genesis' );
  }

  // Hold units of time in seconds, and their pluralised strings (not translated yet).
  $units = [
    /* translators: %s: Number of year(s). */
    [ 31536000, _nx_noop( '%s year', '%s years', 'time difference', 'genesis' ) ],  // 60 * 60 * 24 * 365
    /* translators: %s: Number of month(s). */
    [ 2592000, _nx_noop( '%s month', '%s months', 'time difference', 'genesis' ) ], // 60 * 60 * 24 * 30
    /* translators: %s: Number of week(s). */
    [ 604800, _nx_noop( '%s week', '%s weeks', 'time difference', 'genesis' ) ],    // 60 * 60 * 24 * 7
    /* translators: %s: Number of day(s). */
    [ 86400, _nx_noop( '%s day', '%s days', 'time difference', 'genesis' ) ],       // 60 * 60 * 24
    /* translators: %s: Number of hour(s). */
    [ 3600, _nx_noop( '%s hour', '%s hours', 'time difference', 'genesis' ) ],      // 60 * 60
    /* translators: %s: Number of minute(s). */
    [ 60, _nx_noop( '%s minute', '%s minutes', 'time difference', 'genesis' ) ],
    /* translators: %s: Number of second(s). */
    [ 1, _nx_noop( '%s second', '%s seconds', 'time difference', 'genesis' ) ],
  ];

  // Build output with as many units as specified in $relative_depth.
  $relative_depth = (int) $relative_depth ?: 2;

  $i = 0;

  $counted_seconds = 0;

  $date_partials        = [];
  $amount_date_partials = 0;
  $amount_units         = count( $units );

  while ( $amount_date_partials < $relative_depth && $i < $amount_units ) {
    $seconds = $units[ $i ][0];
    $count   = (int) floor( ( $since - $counted_seconds ) / $seconds );
    if ( 0 !== $count ) {
      $date_partials[]      = sprintf( translate_nooped_plural( $units[ $i ][1], $count, 'genesis' ), $count );
      $counted_seconds     += $count * $seconds;
      $amount_date_partials = count( $date_partials );
    }
    $i++;
  }

  if ( empty( $date_partials ) ) {
    $output = '';
  } elseif ( 1 === count( $date_partials ) ) {
    $output = $date_partials[0];
  } else {

    // Combine all but last partial using commas.
    $output = implode( ', ', array_slice( $date_partials, 0, -1 ) );

    // Add 'and' separator.
    $output .= ' ' . _x( 'and', 'separator in time difference', 'genesis' ) . ' ';

    // Add last partial.
    $output .= end( $date_partials );
  }

  return $output;

}