Cutting Out a Daytime Nap

Hi!

I have a 21 month old DS, and for the past week he has pretty much refused to have a nap in the afternoons! He usually gets up around 8.30, and then has a nap about 2.30 for about an hour and a half or so. But the last few days, he will scream when I put him down and then only sleep for 20 minutes, before waking up in a foul mood.
Today we let him go without having a nap, and he was perfectly fine, all day! Did not get tired and was perfectly happy!
I always thought he was a bit young to be cutting out naps all togeher! When did your children stop having their day time naps?
Thanks

Our DS is almost 20 months and he still has a day sleep. His routine is a bit different - he is an early riser usually about 6.30ish and has a sleep from around 12 to 1.30. He goes to bed at 7.30pm and sleeps through (he's only just got the sleeping through thing in the last 2 months though!).

Perhaps if your DS has more sleeping time o/n then maybe he doesn't need a day sleep. I know our little man would be feral without his!