"Post-Meridian" refers to the time period after noon, specifically from 12:00 PM to 11:59 PM. The term is derived from Latin, where "post" means "after" and "meridian" means "midday." This designation helps distinguish between morning hours (AM) and afternoon/evening hours (PM) in timekeeping. In everyday usage, "Post-Meridian" is often abbreviated as "PM." For example, 3:00 PM indicates three hours after noon. This system is widely used in many countries to organize daily schedules, including activities, appointments, and events, making it easier to communicate time effectively.