The night will not match the chart
Someone will tell you their baby slept through at ten weeks. Smile and ignore the number. Your baby is not their baby, and the range on the page is wide on purpose.
Raising Children says babies need sleep to grow, and the amount varies the way adult sleep varies. The clue is mood, not a cousin. Wakeful and grizzly can mean they need more sleep.
Wakeful and pleased can mean they are getting enough. A happy baby who is awake is not a problem for you to solve with a darker room and a stronger opinion.
At 2 to 3 months, most babies sleep 14 to 17 hours across the day and night. Cycles run about 50 to 60 minutes. Active sleep is the grunting, moving kind.
Quiet sleep is the still kind. At the end of a cycle they surface. They may grizzle.
They may need you to settle the next one. This is also when night and day start to separate, slowly. You help that by keeping nights dull and days brighter, not by refusing a feed because a book said the liver changes at midnight.
Around 3 months the total is often still 14 to 17 hours, with longer cycles. Light sleep, deep sleep, dream sleep. Some babies give you a 4 or 5 hour night block.
Some do not. A block is a gift, not a contract.
From 3 to 6 months the total for most is 12 to 15 hours. Day sleeps often become 2 or 3, up to about 2 hours each. Nights lengthen.
A 6 hour stretch by 6 months happens for some. Expect at least one wake anyway. If you planned your personality around sleeping through, unplan it.
From 6 to 12 months, sleep lessens again. Around the first birthday, 11 to 14 hours in 24 is the likely total. Longest sleeps at night.
Many are ready for bed somewhere between 6pm and 10pm, and often asleep in under 40 minutes, though some take longer. Wakes can drop. They can also be 3 or 4 times, with an adult needed to resettle.
Day naps are often still 2 or 3, half an hour to 2 hours. You are not failing because 7pm does not work. You are failing only if you pretend a 10pm baby is a 6pm baby and then fight them.
The direction over the year is less daytime sleep, longer nights, fewer wakes, less sleep overall. Hold the direction lightly. Track this baby's mood for a week before you buy a program.
Your half of the night can be the resettles after a feed, the dark, the boring voice, the return to the cot. She does not have to be the only person who knows how this baby goes back to sleep.
Source: Raising Children Network