Yes, orders in the premarket session can be entered and executed Monday to Friday between 7:00 a.m. and 9:28 a.m. ET, and orders in the after-hours session can be entered and executed between 4:00 p.m. and 8:00 p.m. ET with the exception of holidays and when a certain asset is halted or suspended. If you place an order outside these hours, you may choose to schedule your order as a Market-on-Open, which will be executed at the market opening on the next business day.
However, it is possible that your order may be executed in whole or in part, or you may not receive as favorable a price as when the market is open due to the lack of liquidity in extended hours trading.