RE: When did you stop using diapers at night?
It sounds like he is doing terrific! It probably took a month or so, before I did not have to "remind" DD to go. And I still remind her before we leave the house to make things easier.
I would master daytime before tackling nighttime. Nighttime bladder control is a whole different issue than daytime. It is perfectly normal for a child to be 4 or even 5 before mastering nighttime. Although some do it much earlier.
My DD still wears a pull-up at night, but I think she could do it at nighttime if we worked on it. But honestly, since in a few weeks I will be getting up with a baby several times a night, I have no desire to add waking up with DD to help her go potty too!
ETA: How much liquid does he consume during the day? You may want to cut back. At 34 months (when my DD trained too), I switched her to a regular cup and that helped tremendously with potty training. I think it can be really hard for them to hold it when they are regularly consuming 8 ounce sippies of liquid.
HTH,
Beth, mom to older DD (8/01) and younger DD (10/06) and always missing Leah (4/22 - 5/1/05)