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Ask HN: What does 12:00 AM mean?

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Re: Ask HN: What does 12:00 AM mean?

#91

Post by hnbad »

nilstycho wrote: post #83
rogual wrote: post #16

Imagine if 12AM meant 12 noon. What would one second past 12 noon be? It'd have to be 12:00:01 PM. Even one millisecond past 12 noon would be PM. So "12AM" could only exist for an infinitesimal length of time, in contrast to 11AM, 10AM etc. which each last for an hour.

There's a misalignment between the sequential numbers (begin at 1:00; end at 12:59) and AM/PM (begin at 12:00; end at 11:59). A 24-hour clock fixes this, but if we insist on a 12-hour clock we could still align these two spans by renumbering the "12" hours as "0" hours. Then we would see 11:59 AM -> 0:00 PM -> 0:01 PM.

Good luck. Americans will insist that 12 is more intutive because zeros look weird or something. If you tried to standardize on 0-based 12 hour clocks in the US it'd probably result in something weird like Texas seceding or some Christian sect claiming it's anti-Christian and trying to assassinate you.

Re: Ask HN: What does 12:00 AM mean?

#92

Post by kashyapc »

It reminds me of a similar problem I face in Dutch (and still trip up if I'm not conscious):

In Dutch (my 4th language), "half nine" ("half negen") means 8:30. Whereas in English[1] "half nine" means 9:30.

So there were times when I missed appointments by an hour! After 7 years of being immersed in the language, I still have to deliberately engage my brain whenever someone says "half nine" (or whatever the hour) in Dutch to carefully translate it to the correct time.

[1] British and Irish English only? Others can correct me here.

Re: Ask HN: What does 12:00 AM mean?

#94

Post by tomrod »

Ensorceled wrote: post #59
tomrod wrote: post #14

That sounds really frustrating. I'm sorry that happened to you. Time is a hard programming and engineering problem. Adopting a global UTC on a 24 hour clock would resolve most of this, but people are entrenched.

I force everything to 24hr UTC time on projects I'm involved with. Then if it's a technical project, display it as 24hr with timezones and if it's not technical then apply all these strange time display rules as user configurable. Solves so many problems. Now, Django supports this pretty cleanly so it's often pretty easy to enforce and work with.

Future maintainers thank you!

Re: Ask HN: What does 12:00 AM mean?

#95

Post by howeyc »

kashyapc wrote: post #92

It reminds me of a similar problem I face in Dutch (and still trip up if I'm not conscious): In Dutch (my 4th language), "half nine" ("half negen") means 8:30 . Whereas in English[1] "half nine" means 9:30 . So there were times when I missed appointments by an hour! After 7 years of being immersed in the language, I still have to deliberately engage my brain whenever someone says "half nine" (or whatever the hour) in…

usually someone would say "half past nine" I'm not sure I've actually heard it your way

Re: Ask HN: What does 12:00 AM mean?

#96

Post by technobabbler »

kashyapc wrote: post #92

It reminds me of a similar problem I face in Dutch (and still trip up if I'm not conscious): In Dutch (my 4th language), "half nine" ("half negen") means 8:30 . Whereas in English[1] "half nine" means 9:30 . So there were times when I missed appointments by an hour! After 7 years of being immersed in the language, I still have to deliberately engage my brain whenever someone says "half nine" (or whatever the hour) in…

In the United States we do not say "half nine". We'd say "half PAST nine" sometimes but honestly "nine thirty" is a lot more common.

Re: Ask HN: What does 12:00 AM mean?

#97

Post by reedf1 »

chekibreki wrote: post #90
kayodelycaon wrote: post #76

Earlier quoted context omitted.

Google searched "why shouldn't I use retarded as an insult" and came up with this result: https://www.verywellfamily.com/what-is-the-r-word-3105651

Quoted post unavailable.

No post body was provided.

Re: Ask HN: What does 12:00 AM mean?

#98

Post by technobabbler »

thanatos519 wrote: post #86
dijit wrote: post #10

Ante meridium and post meridium. Ante- meaning “before”, meridium meaning “highest point of the sun” as in when the sun crosses the “meridian” which would be the line in which it is now setting instead of rising. Passing from post-meridian to ante-meridian is exactly 12 hours from when the sun passed the meridian point, to keep it “consistent”. I get though that it’s confusing, I questioned it a lot as a young boy. P…

I already used 24 hour time and ISO8601 date formats when I lived in Canada (up until 12 years ago). It's like using metric. Just use it.

If you can convince my government and my CEO, I'm game!

Re: Ask HN: What does 12:00 AM mean?

#99

Post by technobabbler »

sonicggg wrote: post #70
Quikinterp wrote: post #5

A lot of my exams will use the time 11:59pm instead of 12:00am to avoid confusion like this

That was common in my university as well, for the same reason. I think OP's school lacked some common sense with the schedule.

I don't think this is a scheduling thing but a cultural thing.

11:59pm would be 23.59 in other places. The mere use of "11" would suggest morning.

Re: Ask HN: What does 12:00 AM mean?

#100

Post by prmoustache »

moralestapia wrote: post #84
prmoustache wrote: post #65

Earlier quoted context omitted.

We do but 12 is noon for us, otherwise past 11:59 in the evening it goes back to 0.

Do your analog clocks have all numbers from 0-23 in them?

No only a small number exists but most are still 12h analog clock.

Anyway that is not really the problem, we just learn from being kids that 12 is only valid for noon otherwise it is implicitely 0 as the next one is 1 anyway. And, at least in my country, we rarely say 12 as we use our words to say midnight/noon.

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