You may choose the validity period of your order to be either GTD or GTC.

GTD (Good 'til Day)
This allows you to place a buy or sell order at a particular price and the order will stay active unless executed or till the day ends.

GTC (Good 'til Cancelled)
This allows you to place a buy or sell order that will stay active until the price is reached or until it expires (within 90 days of the order date).

Please note that Market Orders are executed immediately while limit and stop orders have GTD/ GTC functionality.