I think it is more the age your LO is right now...I won't speak for everyone, but it sounds like your baby is not even 3 months old yet. Lily was up at all hours of the night until she was about 3.5 months old (actual age)!
My DS had his days and nights mixed up for a while. We would turn on lights and open curtains during the day to make it bright and then keep his room very dark at night. It seemed to help. Like the pp said, it could just be the age.
Re: Sleeping problems, mostly at night?