Newborns sleep for about 16 hours out of every 24, split into periods of 2-4 hours and divided equally between day and night.
Most can distinguish night from day by 10 weeks. By the end of the third month, the frequency of daytime naps drops from about four to three and most babies will start to sleep for a longer stretch of around 6 hours a night.
Things are changing rapidly, with sleep dropping to about 14 hours a day. Most babies will sleep around 10 hours during the night and 4 hours in the day.
Although by 3-4 months babies are biologically capable of sleeping through the night, many of them will still wake up at intervals. The good news is they are increasingly responsive to routines.
A distinct shift happens in the balance of day and night-time sleep. By 9 months, most babies need just one morning and one afternoon nap.
Length of naps and night-time sleep becomes more predictable, moving towards 11-12 hours at night (either in one block or shorter bursts) and 2.5 hours in total during the day. This should give you a chance to plan around their sleep.