It can be sold at any time during trading hours, and futures can be sold on the day of purchase. You can't trade outside trading hours. Futures trading hours are: Monday to Friday, 9: 30 am-11:30 pm-15: 00 pm.
Futures night trading hours: Monday to Friday, the market opens at 2 1: 00 pm and closes at 2:30 am the next day. Monday night trading time is from 2 1: 00 last Friday to 2: 30 on Saturday.