My DD is 3 years 2 months and if she misses her day sleep she will be in bed by 6.45pm. My DD1 had a day sleep until she was 5, so I think my kids need their sleep!!
I was told at one stage by our homeopath to try putting her to bed earlier (this is DD2 when she was 2.5years) and he suggested 6.30pm and that included day sleep (from about 11.30am-1.30pm). xo