PHP : Get human readable time difference between 2 dates

get-date-diff.php

<?php
/**
 * Get human readable time difference between 2 dates
 *
 * Return difference between 2 dates in year, month, hour, minute or second
 * The $precision caps the number of time units used: for instance if
 * $time1 - $time2 = 3 days, 4 hours, 12 minutes, 5 seconds
 * - with precision = 1 : 3 days
 * - with precision = 2 : 3 days, 4 hours
 * - with precision = 3 : 3 days, 4 hours, 12 minutes
 *
 * @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 );
}

echo get_date_diff( time() - 348900, time() );
// 4 days, 55 minutes
?>