12 o’clock in the afternoon is considered PM. The 12-hour clock system divides the day into two periods: AM (from midnight to just before noon) and PM (from noon to just before midnight).
When the clock strikes 12:00, it marks the transition point between the two halves of the day. Therefore, 12:00 PM refers to noon, which is the time when the day is halfway over. On the other hand, 12:00 AM is midnight, signaling the start of a new day.