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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?

#171

Post by xiwenc »

njkleiner wrote: post #116

Okay, I'm genuinely confused now, can someone please explain this to me? First of all, how is nobody taking about the fact that OP was scheduled for an exam that takes place... at midnight. There are two possible cases here. Some people are alleging that OP lives in the same place as the exam takes place -- which is not clear to me from the information available -- and use this as an excuse for saying "OP should adop…

OP here. The online exam is run by Pearson Vue. With my brief research I found it’s a British company. That could be the reason they use AM/PM.

I think with better UX on their scheduling app this would have been avoided. Imagine how much cost they could save with minor improvement. It wasted the proctors, customer service and my time. Unless they don't acknowledge own fault and require customers to pay for another exam.

But the thing that made me realize is that the root case is the time notation itself. Imagine how much frustration and unnecessary expenses this could inflict in general.

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

#173

Post by hnbad »

softwarebeware wrote: post #140
hnbad wrote: post #88

Earlier quoted context omitted.

FWIW there are very few moments in time and space where the sun will have reached its highest point at exactly 12:00 PM so even that logic is nonsensical. The only consistent mental model is that for traditional reasons clocks go from 1 to 12 and 12 is actually the zero point of the next 12 hour cycle. It's literally just a cultural artefact you have to commit to rote memorization because there's no good reason for i…

It has more to it than just being a cultural artifact. I think it’s fascinating that ancient cultures preferred a duodecimal system: https://en.m.wikipedia.org/wiki/12-hour_clock

The 12 hour cycle is fine. The problem is that it starts at 12 and then rolls over to 1, rather than starting at zero. You can have a duodecimal system without starting at 12.

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

#174

Post by Markoff »

Pff, this is nothing, I was just today explaining to client that phrase "...will switch off at VARIABLE midnight." where variable is number 12 is complete nonsense, maybe it is acceptable in English, but certainly not in most of the languages, since midnight is midnight and there is no 12 or 24 midnight, it's either 12PM, 24:00 OR midnight, but not some digit together with midnight

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

#175

Post by Markoff »

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.

12 AM and 12 PM makes no sense, because none of them really means noon, while both of them are 12 before noon and 12 after noon

just because you got used to meaning of this nonsense, it doesn't mean it's right

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

#176

Post by alkonaut »

technobabbler wrote: post #30

You have to learn other cultures' norms if you want to live or work with them. It goes both ways. Europe and America do not only time differently, but phone numbers (1-800-123-1234 in the USA, 06 86 57 90 14 in France), dates (Jan 1 1911 would be 1/1/11 in the USA, 11-1-1 elsewhere), decimals (1,000.00 or 1.000,00), units (inches vs centimeters), reading order, daylight savings time, time zones (some countries don't…

That there is some diversity we must cater for, there is also diversity we should cater for while pushing for uniformity (and optionally ridiculing the obviously inferior solutions such as imperial measurements, non iso dates or 12-hour clocks).

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

#177

Post by Markoff »

GoodbyeMrChips wrote: post #154
dccoolgai wrote: post #134

Earlier quoted context omitted.

https://militaryconnection.com/military-time/amp/

Errrrm.... That's an ordinary 24 hour clock. Rather bizarre to call it "Military" time.

military time is spoken in hundreds and doesn't use colon, while regular 24hr time is spoken in dozens and use colon

Military 1400 - fourteen hundred 1430 - fourteen hundred thirty

Standard 24h 14:00 - fourteen hours 14:30 - fourteen thirty

But I am not native English speaker and this is only my understanding from what I observed about military time vs 24 hours time and I may be wrong, someone please correct me.

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

#178

Post by Markoff »

rsstack wrote: post #17

When working at international companies that have little interaction between countries (i.e. not so much that it would be standardized, but enough that it would be an issue): eventually everyone learns to write dates and times in both ways (14:00 / 2pm, 4/12 / 12 April). The Europeans think that they're translating for the "dumb Americans who can't count higher than 12", the Americans think they're translating for th…

don't forget to write Berlin time or Beijing time, so people won't be confused about time zones, since some experts write them in some odd UTC/GMT format with + sign which is complete mess especially with summer/winter time in Europe, while all year same time in China

I always write my Chinese colleagues time either in Chinese/Beijing time or Berlin time to clarify what time zone we are talking about, because it's not so obvious since some of them work until midnight or even 1AM local Chinese time

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

#179

Post by rsstack »

Markoff wrote: post #178
rsstack wrote: post #17

When working at international companies that have little interaction between countries (i.e. not so much that it would be standardized, but enough that it would be an issue): eventually everyone learns to write dates and times in both ways (14:00 / 2pm, 4/12 / 12 April). The Europeans think that they're translating for the "dumb Americans who can't count higher than 12", the Americans think they're translating for th…

don't forget to write Berlin time or Beijing time, so people won't be confused about time zones, since some experts write them in some odd UTC/GMT format with + sign which is complete mess especially with summer/winter time in Europe, while all year same time in China I always write my Chinese colleagues time either in Chinese/Beijing time or Berlin time to clarify what time zone we are talking about, because it's no…

And also surprises of non-unique timezone abbreviations. IST is Irish Standard Time (UTC+0/1), Israel Standard Time (UTC+2/3), and Indian Standard Time (UTC+5:30).

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

#180

Post by mikequinlan »

technobabbler wrote: post #30

You have to learn other cultures' norms if you want to live or work with them. It goes both ways. Europe and America do not only time differently, but phone numbers (1-800-123-1234 in the USA, 06 86 57 90 14 in France), dates (Jan 1 1911 would be 1/1/11 in the USA, 11-1-1 elsewhere), decimals (1,000.00 or 1.000,00), units (inches vs centimeters), reading order, daylight savings time, time zones (some countries don't…

> You have to learn other cultures' norms if you want to live or work with them. It goes both ways.

You also need to recognize ambiguity and ask for confirmation when you see it. Even in the US people will get confused by 12AM/12PM; when you see either of those times you should double check to see what the person meant. On the other hand, the person setting the time should also have recognized the possible confusion and clarified (i.e. 12 noon or 12 midnight).

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