Nowadays, there are mainly 2 standard time systems which are the 24-hour and the 12-hour formats. These have been around for a long time, but since we are so used to having our smartphones and tablets telling us what time it is, we sometimes forget how it really works. Therefore, we will try to make it as clear as possible by explaining the differences between these 2 formats as well as their respective history.
What is the 24-hour format?
The 24-hour clock is considered as the most standard and widespread system, particularly in the United States, and also used by the international standard (ISO 8601). Besides, the latter is used in some sectors as well:
- In military communication regulations, such as the United States Navy or United States Marine Corps.
- In medical practices like patient records.
- In text-based interfaces.
- In some computer programs like timestamps in POSIX.
In this time convention, we count the hour from 00.00 to 24.00 which runs from midnight to midnight. Normally the notation 24.00 refers to midnight at the end of the given date. However, some English-speaking countries prevent ambiguities by avoiding 00.00 and using 24.00 and 00.01 instead.
What is the origin of the 24-hour clock?
The 24-hour time system originated in the ancient Egyptian era and has been used for centuries in astronomy, horology, science, and navigation until this day. The first mechanical 24-hour public clock was installed in Italy and then each country began to follow this format and built their own clocks as well. Some of the most famous clocks in the world include the Orloj in Prague, or the Shepherd Gate Clock at Greenwich (London), etc.
Afterward, Sir Sandford Fleming, a Scottish Canadian engineer, and inventor had promoted a single 24-hour clock throughout the world and proposed it as a worldwide standard time zone and a conventional prime meridian (geographic coordinate system). Because of his efforts, the use of a 24-hour system had grown steadily and was nationally adopted in most countries of the world.
How was the AM and PM format created?
The concept of AM/PM came from the division of a day into 2 cycles: one was tracked with the sun’s position while the other one was tracked with the moon’s. Back in Ancient Egypt, people had used a sundial for daytime and a water clock for nighttime. Similar to ancient Romans, they had divided the daytime into 12 equals hours, but the difference is that the night was separated into 4 sections only.
Thereafter, the double-XII system had been forgotten for a while since people had turned to the 24-hour analog clock. Then, in the 15th and 16th centuries, the 12-hour analog dial became famous again because it was a better fit with our daily routines and was generally more practical to use. Consequently, it gradually became the standard for public use throughout Northern Europe and the British Empire.
What do AM and PM mean?
The abbreviation AM/PM originally came from the Latin language. AM is a shortened form of “ante meridiem” which refers to “before noon” while PM means “post meridiem” or “after midday”. Here is how you can tell the time with the 12-hour system:
- AM indicates the time between midnight to noon (24.00-11.59)
- PM is used from noon until midnight (12.00-23.59)
In addition, some people also use 12-noon for 12AM and 12-midnight instead of 12PM.
What are the 12-hour system’s advantages and disadvantages?
The principal reason why people started to use two-12 hour cycles is that it provides a cleaner clock pattern than the 24-hour version. Moreover, it seems easier to calculate the duration.
On the negative side, let’s say you have an imaginary appointment at 12.00 AM on April 20th, which means you should be there on the night of April 19th (the midnight between April 19 and 20). As you can see, it can still be a bit confusing for some people when you look at it that way.
Secrets tips: how to manage the time wisely?
These days we have many devices to help us track time, like wristwatches, analog or digital clocks, mobile phones, and other gadgets. Nevertheless, the most important thing is not to know exactly what time it is, but to actually understand it! Here are some interesting tips about time organization:
- Wake up early and you will have more time to complete your day effectively.
- Have a to-do list and planner. You should plan for a week or a day in advance at the very least.
- Prioritize your tasks and structure your day: list what you will do in the morning, afternoon, and nighttime.
- Focus on one task and achieve it, one task at a time.
- Find work-life balance. Do not forget to add a relaxing time and to integrate hobbies into your daily plan.
- For example, dinner with family and friends, reading, etc.
- Avoid touching your phone in the morning and during the workday.
- Sleep enough for a better tomorrow!
And this was everything you need to know about the time and on how you can use the 24-hour or 12-hour system as you please. However, it is advised to properly learn both of them so you can adjust yourself when communicating with people from around the world, thus, preventing any confusion with time conversion.