Rocky keeps switching between having braces and not having braces, even though the movie spans a total of 2-3 days. For example, when Grandpa first tells the boys to listen to the flower and when Rocky and Colt first meet Jo, Rocky does not have braces. Yet the morning after the ninjas rescue Jo's father (when Grandpa throws an egg at them) Rocky has braces. Rocky also has braces at the pizza parlor.
When Rocky, Colt and Tum Tum are spying on the meeting between Jack and the mayor, the two men agree that the hearing will be held on the following day. That night, the three boys and Jo rescue Jo's father. The next morning, the boys are exhausted and Tum Tum falls asleep leaning against the refrigerator. That night, they attend the Native American ceremony and Grandpa helps them fight off J.J. and his men. The next morning is the hearing. This means that the hearing actually started two days after the meeting.
In addition to the braces goof mentioned above, you can also tell that the movie must have had a lapse in shooting time because Rocky's voice is much deeper in certain scenes. This is most apparent during Rocky and Tum Tum's tango scene where Michael Treanor's voice is drastically lower than it is in the rest of the movie, which probably means this scene was added in after the original shooting.