MB Trading offers four (4) different types of order expirations: Day, Day+, Day-NB (Non-billable), and IOC (Immediate or Cancel).

Day - Day orders stay live until 4:00 pm EST or until filled, whichever comes first.
Day+ - Day+ orders stay live until 8:00 pm EST or until filled, whichever comes first.
Day-NB - Only available on NYSE stocks. Orders will be automatically cancelled and resubmitted after 4 minutes (until 4:00 pm EST or until filled) to avoid the specialist’s fee of $0.0090/share for orders that sit on their books for more than 5 minutes.
IOC - An IOC (Immediate or Cancel) order will attempt to immediately fill as many shares as possible before canceling your order.