A wake window is the amount of time your baby tends to stay awake between one sleep and the next. The duration of this will change by age and stage. Generally, a newborn's wake window may only be 45 minutes, while a toddler's may be 3-4 hours. Many parents use wake windows as one way to think about building their daily routines. Knowing when your baby will likely need to sleep can help you set realistic expectations and offer related wind-down routines at just the right time.