Isaac stopped day sleeps around 19months.
It was gradual; went from sleeping every day to 3 out of every 5, then once a week, then not at all. I used to put him in his cot at the start with a few books for some quiet time which was enough to give us both a quick recharge for the rest of the arvo. He will have the odd nap in the car if we go out late in the afternoon but then he doesn't sleep until 9pm.

It was hard at first, but as we've both adjusted it's so much easier. As someone else mentioned- going out/getting things done is much easier and he goes to sleep much easier at night. His actual sleep hasn't improved but it's not worse either so I guess he was just ready to drop the day sleep.

Good luck, I hope this isn't it, but if it is it's not all bad news