I've never seen this construction before:
for($count=strtotime("January 16 2004"), $i=0; $count < strtotime("January 20 2004"); $count = $count + 8600, $i++)
[man]for[/man]
Try making your for statement a little more coherent. I don't think you can increment two variables at the same time.
I think you are trying to do a loop within a loop
for (count=strtotime....
for ($i=0...