does the date change on a debt everytime it is sold to a new credii agency

No.  The date that the Statute of Limitations begins to run is the date of default i.e. the date you first missed making a payment, but only if you have not made any payments since then.  If you make a payment, then the limitations period starts over again.   Selling the debt to a new debt buyer does not change the statute of limitations.  If it has been more than five years since you last paid on the debt and someone is trying to collect the debt, you may want to speak to an attorney about whether you have a claim under the Fair Debt Collections Practices Act or the Florida Consumer Collection Practices Act.