Yes, 13 installments that will total your current Steem total at the point you begun to Power down. It is explained users must read before clicking.
This time period is designed into Steemit so as there will not be a 'run' on the currency leading to chaos (as happened in Greece when they stopped ATM cash withdrawals then limited them to 20 Euro only....evil banks).
Steemit is a good bank and it allows withdrawals with zero fees.