However, the timing and amount of light needed is different between people. I don't know specifically. But in the announcement for this chat was listed some numbers and websites where you could order a light. You might want to check that out. However, a lot of health food stores also carry them.
Sleep hygiene is very important in the treatment of depression.
It means such things as - going to sleep at the same time each night and getting up about at the same time, not exercising or drinking alcohol or caffeine before sleep, getting your sleep at night and fighting the temptation to sleep in the day, not watching TV in bed. It also includes things like using the bed to sleep - not to watch TV, read, lounge around, etc. In the Northwest - we go for weeks with seeing much daylight because of the rain, fog, and short days. Getting out and walking is good in its own right - it gets those endorphins working and fresh air improves ones mood. But one might still need light therapy.