get time difference

time_diff.php

<?php
function minuteDiff($str_interval, $dt_start, $dt_end, $relative = true){
    if( is_string( $dt_start)) $dt_start = date_create( $dt_start);
    if( is_string( $dt_end)) $dt_end = date_create( $dt_end);

    $diff = date_diff( $dt_start, $dt_end, !$relative);

    switch( $str_interval){
        case "y":
            $total = $diff->y + $diff->m / 12 + $diff->d / 365.25; break;
        case "m":
            $total= $diff->y * 12 + $diff->m + $diff->d/30 + $diff->h / 24;
            break;
        case "d":
            $total = $diff->y * 365.25 + $diff->m * 30 + $diff->d + $diff->h/24 + $diff->i / 60;
            break;
        case "h":
            $total = ($diff->y * 365.25 + $diff->m * 30 + $diff->d) * 24 + $diff->h + $diff->i/60;
            break;
        case "i":
            $total = (($diff->y * 365.25 + $diff->m * 30 + $diff->d) * 24 + $diff->h) * 60 + $diff->i + $diff->s/60;
            break;
        case "s":
            $total = ((($diff->y * 365.25 + $diff->m * 30 + $diff->d) * 24 + $diff->h) * 60 + $diff->i)*60 + $diff->s;
            break;
        }
    if( $diff->invert)
        return -1 * $total;
    else 
        return $total;
}
?>