php - Convert Time to Integer and Multiply to another Integer -

i've been trying solve day. searched net possible more close enough solution problem. found little bit same problem conversion of time don't know if integer.

to make more clear i'm trying convert time (ex. 00:01:20) integer , multiply in intger (ex. 208). i'm trying mimic how can multiply integer time in excel no avail. derived different number whenever tried convert product of two. i'll show how did make more clear. pardon me resorting because couldn't figure out , i'm not pro in php. thank in advance possible solution this.

    $time = '00:01:20';     $number = 208;     $converted = strtotime($time);     $a = $converted * $number;     $b = date("h:i:s",$a); 

the result on 06:10:24 wrong if going on excel 04:37:20

i'm having hard time trying figure out on how can make appear same excel. thank much.