Nap and Bedtime Changes for 3.5 Year Old

Go by your son's cues.
My son was like that. VERY regular about naps and bedtime.
He was napping even at Kindergarten.
And needed to.

BUT... the thing is, everyday is different, and as they get older. So you have to know the cues of your child, per nap needs and bedtime needs.
IF your child still needs a nap on some days, then do so. But if he does not, then no need to.
And per bedtimes, well my son would still go to bed at his bedtime and his naps did not interfere with that.
My son, no matter if he napped or not, and went to bed at his bedtime, he would STILL wake up the next morning at the same time. 6-6:30am. Every morning.

Kids, are changing developmentally.
At this age, they need to wind down, before bedtime. ie: set the stage for bedtime. Make the house quiet, make it dark (I'd only leave on 1 lamp for example) and key things down. No horseplay or hyper play before bed. Otherwise, the child cannot wind down, for bedtime. With my son, horseplay with Daddy before bed, only got him TOO wound up and "awake" again. And then he couldn't fall asleep nor wind down. And then it would take another HOUR, just to get him wound down, again, for bedtime. For example.

Also, kids this age need physical activity. Running around outside. I would do this in the mornings. Then an early lunch. Then nap time. My son would nap for 2 hours. Routinely. It was just how he was. And I was lucky. Not all kids at that age, nap for that long.

IF you eliminate naps... keep in mind, that on days your son DOES need a nap, then he needs to nap.
If my son did not nap... he would be a GRUMPY fussy monster, by evening time. And my son would even tell me he was tired and wanted to nap.

Go by your child's, cues.

Eliminate naps, most people will take naps, doesn't mean they really need them and if you aren't able to fall asleep at night then that means the nap wasn't a good idea right?

Mine had naps removed around 2, they wouldn't go to bed cause they didn't need the sleep. they went to bed at 7 and would get up at 7. Well not my youngest, she needs even less sleep (3) and tends to get up around 5...no matter what time she goes to bed.

As he is getting older his sleep requirments will change. At 3.5 he likely only needs 10-11 hours a day. If you want him to have an earlier bedtime then you may have to take away the naps, or you could wake him up earlier in the morning. If you don't mind the naps, then keep the later bedtime. My boys had given up naps by the time they were three, and were sleeping from 10:00pm to 8:00am.

I recently cut off my daughter's naps, and she won't be 3 until May. I realize every child is different, but with her naps, she was up until 12 every single night...and it was usually an early nap. I didn't even mean to necessarily take her naps away, but I quit nursing her during the daytime (ONLY at bedtime now) and she's so tired by the end of the day, her new bedtime is 7 or 8, depending on her mood. She is happy and ready to go to bed now, and sleeps well.

Try eliminating the naps for a few days to a week to see if it helps!

this is a rough stage... my son made it to 4 with a nap. then if he took a nap -- he wouldnt go to sleep at night.. so i tried to shorten naptime to 1 hour.. but I couldnt wake him up after an hour and he was a grumpy bear..when i did get him up..

so.... I took about a week and wrote down the times that he actually slept at nap and at night... and figured out he needed 11.5 hours of sleep.. so if he went to bed at 730 at night.. he would get up at 7 am..

i gave up on naps.. but some afternoons he was tired and grumpy. but overall life was better without a nap.. but he will need to make at the time he was napping with more nighttime sleep. so move bedtime earlier..

I'd start by cutting out a few naps a week. Maybe have him not nap on MWF and see how it goes.

My 3.5 yr old is in the same boat--he was very easy to put to sleep until recently, so we have cut down on the naps. Now he only naps about 2 days a week (I usually choose Sunday as one of those days, so I can get a good nap too ;-)