Gina dropped her day sleep a couple of months ago now - so at around 2.5 years. She just started refusing to go to sleep and doesn't appear tired. We get her to do some quiet stuff ie read books, draw to give her a rest (and us too) but we let her be mostly. She goes to bed at 8-8:30 in the evening and wakes up around 7-7:30.
Emma (who loves copying Gina) is working on dropping her sleep at the moment and only sleeps for around 30 min or sometimes not at all.

She does get quite tired & grumpy and the only thing that seems to work is putting her to bed early in the evening - tonight she went to bed at 7pm - it does mean that she'll wake up at 6am though