My father is a 67 yr old diabetic. His landlord sent him a certified letter in the mail. The letter was NOT a legal document...ie, not from a court, stating he had 15 days to vacate his rental property for non payment of rent. Which is true, he has not paid rent and has been actively searching for a new home. My question is, since the letter was not a legal form, how long will he actually have to leave?