Checking length of time?

[disciple <disciple@exis.net>]

I have set up a bare debian system that allows internet sharing through 
a dial up connection.  My ISP only allows 8 hours of a constant 
connection b4 they log you off.  I have 2 questions.

1. How do I check the status of the connection... ie the length of time 
that my debian box has been connected?

2. How can I set my box up to automatically disconnect after say about 
7.5 hours, and then reconnect?

Thanks everybody...  This forum has been a huge help in my transitioning 
to Linux.