You've only been doing it a week... going to bed at 5pm when it is sunset is well and good in February. Come summer time trying to tell your body to sleep when the Sun is high in the sky might be a big problem. Certainly not impossible but it might not feel so great for you. I fell into a very natural (seeming) sleep pattern from 8am - 3pm which worked for me at the time. That was a lifetime ago though and it simply isn't practical for me now.