Eight months is when a settled sleeper often stops sleeping, and it is almost always developmental rather than anything you did.
Most 8 month olds land on 12 to 15 hours of sleep across 24 hours, 2 naps, and wake windows of roughly 2.5 to 3.5 hours. Shortest window first thing in the morning, longest before bed.
A day that actually works
| Time | What happens | Wake window |
|---|---|---|
| 7:00 | Wake and first feed | - |
| 9:45 | Nap 1 | 165 min |
| 11:15 | Wake, feed | - |
| 14:15 | Nap 2 | 180 min |
| 15:45 | Wake, feed | - |
| 19:15 | Bedtime routine, then bed | 210 min |
The times are a sketch. The wake windows are the part worth holding onto, because they are what stops a baby arriving at a nap already overtired.
The thing to get right at 8 months
Crawling, pulling up and babbling all land around now, and babies practise them at 2am. The 8 month regression is mostly motor-skill rehearsal.
An 8 month old will fight sleep because something more interesting is happening, not because they are not tired. Cues get less reliable again for a couple of months. Watching the clock beats waiting for cues at every age under one, and a baby who is past the window fights the nap you were trying to give them.
Night sleep at 8 months
Night waking commonly returns at 8 months after weeks of good sleep. The waking is real, it is developmental, and it usually resolves in two to four weeks without any change to the routine.
Two babies practising crawling at 5am
Two babies practising crawling in one room at 5am is a specific kind of problem. Room-sharing twins often need a fortnight apart at this age, then go back together fine.
Everything above applies to each baby on their own, which is the problem: two babies on separate schedules means nobody is ever asleep at the same time. One decision does most of the work, and it is the morning. Wake both babies within about half an hour of each other and the rest of the day follows. During the day the rule flips, though: let a nap finish rather than rousing the second baby, then shorten the next wake window for whoever is running ahead.
If your twins were born early, use corrected age for all of this. A baby born eight weeks premature follows a schedule about eight weeks behind their calendar age, and the smaller twin often needs slightly shorter windows than their sibling.
Where it usually goes wrong
Babies who have just learned to pull up often wake, stand in the cot, and then cannot work out how to get down. Practising lying down during the day genuinely shortens this.
What changes at 10 months
Night waking that starts here usually resolves in two to four weeks without changing anything, provided daytime sleep stays steady.
Where the app fits
What helps at this age is a record, not more advice. Multibaby lets you see at a glance whether the 3am waking is both babies or one, which decides whether you are dealing with a phase or a room-sharing problem. The wake window calculator will do the arithmetic for a single nap if you just need the next one.