How often is your 4 month old sleeping? Mine is sleeping just about every hour for about 30 mins to a hour each nap. She can't be awake for more than a hour without being super cranky.
LO is just about 5 months and mostly take short naps throughout the day of 15-30 mins after eating. Sometimes if she's really tired she might nap for an hour in the afternoon too.
She is typically taking 4 naps a day. Late morning, Noon-ish, afternoon, and early evening. The length of the naps is more varied then the actual time she takes them. They can last anywhere from 30-90 minutes. Her morning and afternoon naps seem to be her longest and the early evening nap is usually short.
DD is almost 4 months and sleeps anywhere from 30mins - 2 hours and is awake about 1.5-2 hours in between naps. She usually does a short 30 min nap in the morning, a long 1.5-2 hour nap in the middle of the day and then 1 or 2 another short naps about 30-40 mins long.
My LO is awake for no longer than 1.5 hours before he needs to go down for a nap. Sometimes he'll be awake for 2 hours or longer if we are away from home in a really stimulating environment, but then he'll crash in the car on the way home almost immediately.
Re: Nap schedule