Winter days can be a bummer. Your fix: Wake up sooner.

A recent University of Toronto study finds early risers generally have a more positive outlook on life than their sleepyhead counterparts.

One possible reason? They max out daily exposure to morning light, which boosts mood-lifting serotonin.

If you're a night owl, here are 3 painless ways to get up earlier. You too can rise--and shine all day.

1. Move your wake-up time back in 10-minute increments over the course of a few days--your body will more easily acclimate to the change.

2. Stick to your schedule on weekends as much as possible. Waking up around your normal weekday hour at least one weekend morning can help your body stay on track.

3. Maximize exposure to natural rays by putting on your makeup or eating breakfast in front of a window. Even better, take a quick walk before you head to work.