Post meridiem, commonly abbreviated as PM, is a term used to indicate the time period after noon. The phrase itself is derived from Latin, with “post” meaning “after” and “meridiem” referring to noon or midday. The usage of post meridiem can be traced back to the ancient Romans, who divided the day into two halves – ante meridiem (before noon) and post meridiem (after noon). This division of time was particularly important in Roman society, as it helped in organizing various activities and events.
In Latin, the word “meridiem” is in the accusative singular form, indicating that it is being used to describe a specific time period. The term post meridiem was later adopted by various languages, including English, to denote the time after noon. It provides a concise and universally understood way of indicating whether a given time is in the morning or afternoon.
The concept of dividing the day into two halves based on noon has been prevalent in many cultures throughout history. For instance, ancient Egyptians also divided the day into twelve hours from sunrise to sunset and twelve hours from sunset to sunrise. However, the Romans were the ones who popularized the use of post meridiem as a specific designation for the time after noon.
Nowadays, the 12-hour clock system is widely used in many countries, and the designation of AM (ante meridiem) and PM (post meridiem) is commonly employed to differentiate between morning and afternoon hours. This system has become ingrained in our daily lives, from scheduling appointments and meetings to catching flights and trains.
Having a clear distinction between morning and afternoon is essential in various aspects of our lives. It helps us plan our day, allocate time for work, leisure, and social activities, and synchronize our activities with others. The use of post meridiem allows for effective communication and avoids confusion when discussing specific times.
In my personal experience as a sommelier and brewer, the concept of post meridiem is particularly relevant when it comes to organizing wine tastings or beer brewing sessions. For example, scheduling a wine tasting event in the afternoon ensures that participants can fully appreciate the flavors and aromas of the wines, as their palates are more awake and receptive compared to early morning tastings. Similarly, when brewing beer, timing is crucial, and understanding whether a particular step is performed in the AM or PM helps maintain consistency and precision in the process.
To summarize, the term post meridiem has its origins in Latin and has been widely adopted in various languages, including English, to denote the time period after noon. This division of the day into morning and afternoon is essential for organizing our daily activities and facilitating effective communication. Whether it's scheduling appointments, planning events, or brewing beer, the concept of post meridiem plays a significant role in our lives.