Can I take the exam in Jin Meng in the afternoon and morning?

You can't.

According to the query of traffic control 12 123, the appointment time can't be changed casually, and the exam in the afternoon can only be held in the afternoon, because the number of people and information in the morning are also certain, so we should go earlier in the afternoon.

Subject 3 is the abbreviation of road driving skills and common sense of safe and civilized driving in motor vehicle driver's examination.