The clock shows you the time. Time helps you plan your day. But two letters, AM and PM, often cause people problems.
What do they really mean? This is the simple question behind “AM of PM betekenis.” If you mix them up, you might miss a flight or show up for work at 7 at night instead of 7 in the morning.
This guide makes it simple. We will look at what AM and PM mean. We will learn where they come from. You will see how to use them right every single time. Get ready to know the 12 hour clock perfectly.
AM and PM: What the Letters Mean
AM and PM are short forms of two old Latin phrases. They split the day into two parts.
What Does AM Mean?
AM stands for Ante Meridiem.
- Ante means “before.”
- Meridiem means “noon” (the middle of the day).
AM means “before noon.”
The AM time starts at 12:00 AM (midnight). It runs until just before 12:00 PM (noon). This is when you sleep, wake up, eat breakfast, and start school or work.
- Example: If you set your alarm for 6:00 AM, you wake up in the morning.
- Fact: The AM period lasts for 12 hours.
What Does PM Mean?
PM stands for Post Meridiem.
- Post means “after.”
- Meridiem means “noon.”
PM means “after noon.”
The PM time starts at 12:00 PM (noon). It runs until just before 12:00 AM (midnight). This is when you eat lunch, work in the afternoon, eat dinner, and go to bed.
- Example: If you meet a friend at 4:00 PM, you meet them in the afternoon.
- Fact: The PM period also lasts for 12 hours.
The Tricky Times: Noon and Midnight
The change points are often confusing. What do we call 12:00? You must know this to schedule things well.
Noon: 12 PM
When the clock hits 12 in the middle of the day, it is 12:00 PM.
Why PM? At the exact moment of noon, the “before noon” (AM) time stops. The “after noon” (PM) time starts. Noon is the start of the afternoon.
To be extra clear, you can just say noon.
- Right: Let’s eat at 12 PM.
- Right: Let’s eat at noon.
- Wrong: Let’s eat at 12 AM noon.
Midnight: 12 AM
When the clock hits 12 at the very start of a new day, it is 12:00 AM.
Why AM? Midnight resets the clock. 12:00 AM is the start of the next 12 hours that come before noon (Ante Meridiem).
Midnight is the moment one day ends and the next day begins.
Danger Point: When you use 12:00 AM, always say which day you mean.
- Clear: The mail goes out at 12:00 AM on Tuesday. (This means the moment Monday ends and Tuesday begins.)
- Confusing: The mail goes out at 12:00 AM. (Is that Monday night or Tuesday night?)
Tip: Many groups use 11:59 PM or 12:01 AM instead of 12:00 AM. This stops all doubt.
Where the 12 Hour Clock Comes From
The system you use every day is very old. It started long ago.
Ancient Egypt
The 12 hour clock began with the people of ancient Egypt. They looked at their hands. They counted the 12 small segments on their fingers using their thumb. This likely made 12 a special number.
They used different tools to tell time:
- Day: They used shadow clocks (like a basic sundial) to track 12 hours from sunrise to sunset.
- Night: They used special stars and water clocks to divide the darkness into 12 parts.
This is how we first got 12 hours for the day and 12 hours for the night.
The Roman Part
The Romans used the system later. They used the Latin words ante meridiem and post meridiem to say if the time was before or after the sun was highest. This is why we use AM and PM today.
The 12 hour clock is still the main way people talk about time in many countries, like the United States.
How to Use AM and PM Right
You use AM and PM all the time. Learn these simple rules to avoid errors.
For Meetings and Plans
Always say AM or PM when you set a time. If you do not, people will guess.
- Avoid: “Meet me at 3.” (Is that three in the morning or three in the afternoon?)
- Right: “Meet me at 3:00 PM.” (Three in the afternoon.)
- Right: “The class starts at 9:30 AM.” (Nine thirty in the morning.)
For Travel and Tickets
Travel schedules must be perfect. A ticket that says 7:00 AM means you must be up and ready early. A time of 10:50 PM means late at night.
What about the 24 hour clock?
Some tickets use the 24 hour clock (like 00:00 to 23:59). This clock makes no mistakes.
- If the number is 13 or higher, it is PM.
- To change it to PM, just take away 12.
- 15:00 is $15 – 12 = 3$ PM.
- 20:15 is $20:15 – 12 = 8:15$ PM.
Using the 24 hour clock is often easier when you travel far away.
Writing the Time
You have choices for how to write the time. Just make sure you are clear and use the same style every time.
- With dots: 7:00 PM (Use the dot called a colon for minutes.)
- On the hour: 4 PM (You do not need the “:00” if it is an exact hour.)
- Small letters: 3 pm (This is common when texting or emailing.)
The main rule is this: Be clear. Be the same every time you write it.
Three Big Mistakes to Stop Making
Even people who know the rules make these small mistakes. Do not be one of them.
1. Do Not Use AM/PM with Morning or Night
The letters already tell you the time of day. Adding more words is too much.
- Bad: We will work at 9:00 AM in the morning.
- Good: We will work at 9:00 AM. (AM already means morning.)
- Bad: The movie starts at 8:00 PM tonight.
- Good: The movie starts at 8:00 PM. (PM already means night.)
2. Always Write the Abbreviation
Do not just leave the time as a number. This causes big problems.
- Unclear: See you at 5.
- Clear: See you at 5:00 PM. (You know if you need to rush or relax.)
3. Use Noon and Midnight if You Can
The words noon and midnight are the clearest way to say 12 o’clock. They take away all doubt about AM or PM.
- Clear: The store opens at noon. (12 PM)
- Clear: We must leave before midnight. (12 AM)
Read: AM of PM Tijd: Explained What Ante Meridiem and Post Meridiem Mean
Conclusion
The meaning of AM and PM is simple: AM is before noon, PM is after noon.
You now know the rules of the 12 hour clock. You know that 7 AM is early, 7 PM is late, 12 PM is the middle of the day, and 12 AM is the start of the new day.
Use this knowledge. Be clear. Make your plans simple and correct. Do not let two small letters cause you a big problem ever again.
Questions and Answers
What does the phrase “AM of PM betekenis” mean in simple English?
It means “AM or PM meaning.” It is asking for a simple answer about what the two time abbreviations mean.
Is 12 AM in the morning or at night?
12 AM is midnight. It is the exact moment a new day starts. Because it is before noon, it is the start of the “morning” time cycle (Ante Meridiem).
Is it better to use AM/PM or the 24 hour clock?
Use AM/PM when you talk to friends or family. Use the 24 hour clock (like 14:00 for 2 PM) for travel, official work, or when you talk to people in other countries. The 24 hour clock avoids all doubt.
What is the simple difference between AM and PM?
AM covers the time from midnight to noon (the first half of the day). PM covers the time from noon to midnight (the second half of the day).
