Get human readable time difference between two given dates

getDateDiff.php

/* @param mixed $time1 a time (string or timestamp)
 * @param mixed $time2 a time (string or timestamp)
 * @param integer $precision Optional precision 
 * @return string time difference
 */

function get_date_diff( $time1, $time2, $precision = 2 ) {
	// If not numeric then convert timestamps
	if( !is_int( $time1 ) ) {
		$time1 = strtotime( $time1 );
	}
	if( !is_int( $time2 ) ) {
		$time2 = strtotime( $time2 );
	}
	// If time1 > time2 then swap the 2 values
	if( $time1 > $time2 ) {
		list( $time1, $time2 ) = array( $time2, $time1 );
	}
	// Set up intervals and diffs arrays
	$intervals = array( 'year', 'month', 'day', 'hour', 'minute', 'second' );
	$diffs = array();
	foreach( $intervals as $interval ) {
		// Create temp time from time1 and interval
		$ttime = strtotime( '+1 ' . $interval, $time1 );
		// Set initial values
		$add = 1;
		$looped = 0;
		// Loop until temp time is smaller than time2
		while ( $time2 >= $ttime ) {
			// Create new temp time from time1 and interval
			$add++;
			$ttime = strtotime( "+" . $add . " " . $interval, $time1 );
			$looped++;
		}
		$time1 = strtotime( "+" . $looped . " " . $interval, $time1 );
		$diffs[ $interval ] = $looped;
	}
	$count = 0;
	$times = array();
	foreach( $diffs as $interval => $value ) {
		// Break if we have needed precission
		if( $count >= $precision ) {
			break;
		}
		// Add value and interval if value is bigger than 0
		if( $value > 0 ) {
			if( $value != 1 ){
				$interval .= "s";
			}
			// Add value and interval to times array
			$times[] = $value . " " . $interval;
			$count++;
		}
	}
	// Return string with times
	return implode( ", ", $times );
}