Forms authorization cookie always set to expire in 2055?

From: Amil (amilhanish_at_hotmail.com)
Date: 07/22/05 

Date: Fri, 22 Jul 2005 09:30:53 -0600

I'm using Forms authorization. In my <forms> section I have timeout="30",
but when I examine the cookie, it shows it expiring in 2055? Why?

   <authentication mode="Forms">
      <forms
         loginUrl="/login.aspx"
         protection="All"
         timeout="30"
         path="/">
         <credentials passwordFormat="Clear">
            <user name="guest" password="xxxxxxx" />
         </credentials>
      </forms>
    </authentication>