function timeAgoInWords($datetime_string, $format = 'j/n/y', $backwards = false, $return = false) {
		$datetime = $this->fromString($datetime_string);

		$in_seconds = $datetime;
		if ($backwards) {
			$diff = $in_seconds - time();
		} else {
			$diff = time() - $in_seconds;
		}

		$months = floor($diff / 2419200);
		$diff -= $months * 2419200;
		$weeks = floor($diff / 604800);
		$diff -= $weeks * 604800;
		$days = floor($diff / 86400);
		$diff -= $days * 86400;
		$hours = floor($diff / 3600);
		$diff -= $hours * 3600;
		$minutes = floor($diff / 60);
		$diff -= $minutes * 60;
		$seconds = $diff;

		if ($months > 0) {
			// over a month old, just show date (mm/dd/yyyy format)
			$relative_date = 'on ' . date($format, $in_seconds);
			$old = true;
		} else {
			$relative_date = '';
			$old = false;

			if ($weeks > 0) {
				// weeks and days
				$relative_date .= ($relative_date ? ', ' : '') . $weeks . ' week' . ($weeks > 1 ? 's' : '');
				$relative_date .= $days > 0 ? ($relative_date ? ', ' : '') . $days . ' day' . ($days > 1 ? 's' : '') : '';
			} elseif ($days > 0) {
				// days and hours
				$relative_date .= ($relative_date ? ', ' : '') . $days . ' day' . ($days > 1 ? 's' : '');
				$relative_date .= $hours > 0 ? ($relative_date ? ', ' : '') . $hours . ' hour' . ($hours > 1 ? 's' : '') : '';
			} elseif ($hours > 0) {
				// hours and minutes
				$relative_date .= ($relative_date ? ', ' : '') . $hours . ' hour' . ($hours > 1 ? 's' : '');
				$relative_date .= $minutes > 0 ? ($relative_date ? ', ' : '') . $minutes . ' minute' . ($minutes > 1 ? 's' : '') : '';
			} elseif ($minutes > 0) {
				// minutes only
				$relative_date .= ($relative_date ? ', ' : '') . $minutes . ' minute' . ($minutes > 1 ? 's' : '');
			} else {
				// seconds only
				$relative_date .= ($relative_date ? ', ' : '') . $seconds . ' second' . ($seconds != 1 ? 's' : '');
			}
		}