Distinguishing AM & PM Differences

AM vs PM

Understanding the difference between AM and PM can be challenging if you are not familiar with what each term represents. AM and PM refer to two different periods of time within a day. AM is short for Ante Meridiem, while PM stands for Post Meridiem. Both abbreviations function as adjectives, as they describe the time of day or night. This article will explain how AM and PM are used in language, what distinguishes them from one another, and which one corresponds to 12 o’clock in the morning and 12 o’clock at night.

What does AM mean?

AM, or ante meridiem, is Latin for “before noon.” Some people mistakenly believe that AM means “after midnight.” This confusion likely arises because the time represented by AM falls between 12 o’clock at night, or midnight, and 12 o’clock, or noon. However, the term “after midnight” may have become popular because it is easier to remember than the Latin phrase, particularly for those not familiar with Latin.

What does PM mean?

PM, or post meridiem, translates to “after noon” in Latin. Since the time before noon is called AM, it logically follows that the time after noon is referred to as PM. It is important to note that 12 o’clock is known as either midnight or noon. For example, in the sentence “I expect you will come at noon,” the word “noon” is understood to mean 12 o’clock in the morning, and the word “midnight” in the sentence “He slept at the stroke of midnight” is understood as 12 o’clock at night. As a result, neither noon nor midnight can be represented by AM or PM. This is a crucial observation to make when using AM and PM to indicate time. Although you may occasionally see midnight represented as 12 PM and noon represented as 12 AM, this is not correct. It is more accurate to say that AM and PM begin immediately after midnight and noon or midday, respectively. Therefore, 00:00 AM and 12:00 PM have no meaning and should be referred to as midnight and noon.

Key Takeaways

• AM stands for Ante Meridiem, meaning “before noon,” while PM stands for Post Meridiem, meaning “after noon.”
• Some people mistakenly think that AM means “after midnight,” but this likely stems from the term being easier to remember than the Latin phrase Ante Meridiem.
• 12 o’clock at night and 12 o’clock in the morning are known as midnight and noon, respectively, and cannot be represented by AM or PM.