When did you drop the nap? How did you know it was time?

[Marigoldy01]

I have twins who will be 3 in a couple months. They have about 1.5hr nap each day but lately haven't been settling at night until almost 10pm! It's been going on for about a month now with bedtime getting later and later. The last two days I have tried to keep them awake all day, which is a struggle they get very tired and cranky and sometimes doze off, but they go to bed at 7-7.30 easily and sleep until 7am.

Is it time to drop the nap? Are they old enough to not need one? What age did your kids stop napping?