You don’t need the am or pm 90% of the time because obviously a lunch date is happening sometime around noon, not midnight. A lunar eclipse or meteor shower isn’t visible while the sun is up, or a midnight snack isn’t happening in the middle of the day. Obviously if you are talking trains and flights, you need AM and PM. But people who are used to 12 hour time don’t want to figure out when 16:00 is, so they don’t.
If you know basic addition and you know how a 12 hour clock functions, then you know how a 24 hour clock functions. If you can’t figure it out, that doesn’t make it inconvenient, it just makes you incredibly stupid.
You don’t need the am or pm 90% of the time because obviously a lunch date is happening sometime around noon, not midnight. A lunar eclipse or meteor shower isn’t visible while the sun is up, or a midnight snack isn’t happening in the middle of the day. Obviously if you are talking trains and flights, you need AM and PM. But people who are used to 12 hour time don’t want to figure out when 16:00 is, so they don’t.
Fun fact: Many countries use both systems actually.
For speaking, it’s quicker to say something like: “The party starts at 8” instead of “The party starts at 20 o’clock”.
For writing though, you would never use the 12 hour system.
If you know basic addition and you know how a 12 hour clock functions, then you know how a 24 hour clock functions. If you can’t figure it out, that doesn’t make it inconvenient, it just makes you incredibly stupid.