calendar/tables

I'm probably doing this the hard way, but I'm trying to make a calendar using tables and I can't get the widths to behave.

You can view it here:
http://metal.czerach.net/calendar.html

When I look at it in Mozilla, it's almost OK, but the columns get progressively smaller. When I look at it in IE, forget about it. It's a mess.

Any ideas? Thanks :)