if you don't live in US east coast, trading companies business h
The New York Stock Exchange, NYSE, is open from Monday through Friday 9:30 a.m. to 4:00 p.m. ET.
Since small trading software firms usually provide "hot-fixes" to their customers, their employees must start about one hour earlier. If they support pre-trade, they must get up at crazily early hours. It's very painful if you are not early bird.