So common, and here's why:
1. In the womb, babies frequently rest on their sides, but we're now instructed to have them sleep on their backs for safety;
2. In the womb, babies are "hugged," snugly and constantly;
3. In the womb, babies always hear a very loud whooshing sound;
4. In the womb, babies are rocked and jiggled constantly during the day while the mother is active.
According to Harvey Karp, M.D., who wrote The Happiest Baby on the Block, those four factors combine to create a "relaxation response" that helps the baby sleep (both before and after birth). That would explain why newborns are more used to sleeping during the day, since that's when they got all that jiggling and rocking.
You can help your little guy sleep by giving him as much of all four conditions as possible during these long nights. As he gets more sleep at night, he'll gradually need less during the day.
Dr. Karp recommends snug swaddling so the baby won't flail and wake himself, and defines his technique in his book. He shows how to hold the baby on his side, or even on his belly on your arm or thigh. He explains why constant, loud noise, from a hair dryer, vacuum cleaner, noise machine, or your voice, is comforting and won't hurt your baby's hearing. And he descrbes how to vigorously swing and jiggle your baby to distract him from his own new, disturbing sensations (as we all know, many infants have trouble accommodating the physical experience of digesting and eliminating; we call it colic).
The holding, jogging, and shooshing techiniques came to me as a result of trial and error. I can't swear to the swaddling, which I've never used, but I have yet to comfort a baby that didn't respond quickly to the other actions, especially holding the little body snug against my chest (side position) or on my shoulder (belly-down position) and jolting my heels on the floor. Instant magic, but it can get exhausting. So adding the swaddling and a source of noise would really help.
Hang in there. The switch will happen. But you can probably speed the process by soothing your son in ways similar to his time in the womb.