Babies are often unable to fall asleep because they don't understand the difference between night and day and need time to adjust to the sunrise-sunset pattern. As a result, their sleeping habits are unpredictable, resulting in insufficient sleep. A newborn baby can sleep anywhere from 10 to 17 or 18 hours each day. Nonetheless, as babies get older, usually within a few weeks, they learn to distinguish between day and night. You can start making efforts to control your baby's sleep patterns around this time.