genuine question - how come when I submit an after hours trade through my bank it says "trading is closed, your order will be submitted first thing tomorrow" ?
It could be your bank just doesn't offer it. For most retail brokerage accounts you have to specifically request an extended "time in force" if you want to send orders outside of the core session.
It's your brokerage. For example, Tradeking allows trading from 8:00-9:30 ET and 4:00-5:00 ET. Some other brokerages, like Interactive Brokers, allow trading to 8:00 PM ET.
Just an FYI, if you trade after hours remember to set your price (buy or sell). As it's after hours, there is no market price, and therefore if you offer to buy 100 shares another party can sell at any price they want. Same goes for the sell side.