old credit card debt

Statutes of limitation depends on the type of debt that you owe, it varies with oral contract, written contract and so on. SOL also differs for different states.

The countdown starts from the date of last activity seen in your account, i.e. from the date you made the last payment towards the account. You can visit this thread to find out the SOL applicable for you-

http://forums.debtcc.com/forums/state-statutes.html