FWIW, and understanding that individual babies do differ, most babies can sleep through the night (10-12 hours) by 3-4 months old. Check out the books "Twelve Hours' Sleep by Twelve Weeks Old" or "Precious Little Sleep" for guidance.
In my case where n=2, naps during the day are/were not all that consistent but at night (unless they are very sick or something) the kids sleep.
In my case where n=2, naps during the day are/were not all that consistent but at night (unless they are very sick or something) the kids sleep.