function timecon ($h1,$h2)
{
if(strlen($h1)>5) $h1 = substr($h1,0,5);
if(strlen($h2)>5) $h2 = substr($h2,0,5);
$h1e = explode(':',$h1);
$h2e = explode(':',$h2);
$h1m = mktime($h1e[0],$h1e[1],0,0,0,0);
$h2m = mktime($h2e[0],$h2e[1],0,0,0,0);
return round(($h1m-$h2m)/60);
}

//timcecon('13:05','12:55') /10