Quote from TRADERguy:
Most of your body's internal clock is regulated by light. Have the lights on at night while you are trading, don't sit there in the dark and trade by the light of your monitors and TV. Keep the blinds drawn while you are trading so your body doesn't think that it is the start of the day during the middle of your day. Make sure that your bedroom is dark when you go to sleep. Don't go outside in the sunlight 60 to 90 minutes prior to going to bed. Also they make some sort of light helmet or box that people use to fight jet lag and to avoid depression during the winter/especially north of the Arctic circle; maybe try using one of these when you get up. Last, make sure that you are getting enough sleep, if your body needs 8 hours quit a little earlier.