2 days - big girl underwear all day, including the car, shopping, and nap.
Lilypad Princess is so proud of her success, she's going without even telling anyone now, emptying the potty herself, and was very upset when I tried to put a diaper on for naptime yesterday. She told me that she isn't a baby anymore. So we picked up some of the thicker, training underwear (thanks for the tip Allison) to use for naptime and in the car. We are down to diapers only for bedtime.