Not wanting to nap

So my son normally takes two naps a day, he wakes up around 8-9 a.m takes his first nap around 11 & is usually awake by 12:30-1 then he’ll take his second nap around 3:30-4 & will wake up from 5-6

It’s already 6 pm and he is not wanting to sleep at all😫 does this mean he is ready to cut down to one nap for a day? Is anyone else’s LO doing this? I’m afraid he’ll get over tired, he normally gets after being awake for 4 hours & the longest he’s gone is 5 1/2 hours and he was extremely cranky

His bedtime is around 9 pm

Ftm here 😅😅