1-4 Weeks Old: 15 - 16 hours per day
Newborns typically sleep about 15 to 18 hours a day, but only in short periods of two to four hours. Premature babies may sleep longer and colicky ones shorter.
Since newborns do not yet have an internal biological clock, or circadian rhythm, their sleep patterns are not related to the daylight and nighttime cycles. In fact, they tend not to have much of a pattern at all
1-4 Months Old: 14 - 15 hours per day
By 6 weeks of age your baby is beginning to settle down a bit, and you may notice more regular sleep patterns emerging. The longest periods of sleep run four to six hours and now tends to occur more regularly in the evening. Day-night confusion ends.
4-12 Months Old: 14 - 15 hours per day
While up to 15 hours is ideal, most infants up to 11 months old get only about 12 hours of sleep. Establishing healthy sleep habits is a primary goal during this period, as your baby is now much more social, and his sleep patterns are more adult-like.
Babies typically have three naps and drop to two at around 6 months old, at which time (or earlier) they are physically capable of sleeping through the night. Establishing regular naps generally happens at the latter part of this time frame, as the biological rhythms mature. The midmorning nap usually starts at 9 a.m. and lasts about an hour. The early afternoon nap starts between noon and 2 p.m. and lasts an hour or two. And the late afternoon nap may start anywhere from 3 p.m. to 5 p.m. and usually varies in length.
1-3 Years Old: 12 - 14 hours per day
As your child moves past the first year toward 18-21 months of age he will likely lose his morning and early evening nap and nap only once a day. While toddlers need up to 14 hours a day of sleep, they typically get only about 10.