If you exceed your day trade buying power you will be issued a day trade call. You will have up to 4 business days to deposit funds to meet the call. During this time, your day trade buying power will be reduced to 2 times your start of day cash and can only be used once for the total of all day trades done for the day.
Until the day trade call is met (or expires in 90 days if not met) you no longer have “time and tick”. This means that if you close a position that you had held overnight and then open a new position in that same security, then this is still considered a day trade and would count towards your day trade buying power.
If you do not cover your day trade call by the due date then your account will be restricted to your start of day cash for 90 days or until funds are deposited to cover the day trade call. If there are any other day trade calls issued during that 90 days then the account would be restricted to sells only for 90 days.