Fourth Nap

The fourth nap is usually dropped between 3-5 months, usually closer to 5 months. Often this nap is dropped when baby transitions to a 4 hour eat/activity/sleep routine although baby may be ready to drop this nap before he
is ready for this. Before this nap is dropped, it usually turns into a catnap by, if not before, 3 months of age.

Often the timing of this nap occurs during a baby's fussy time of day so getting this nap to occur may be difficult for some babies during the early months, especially if they have not gotten enough sleep during the day resulting in overtiredness. If your child is struggling falling asleep and staying asleep at this time, sometimes holding them to sleep in a dark, calm environment for the length of the entire nap for a few days will get their body back into the habit of sleeping at this time.

As I've mentioned before, the waketime usually increases during the day. The waketime after this nap, or before bed, can be pretty variable for babies though. For some it will be a bit longer than the average waketime, for others it will be a bit shorter. With my third child, for the first few months I found that I had to have her asleep within 45 minutes from waking from this nap otherwise she'd get fussy for at least an hour.