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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?

#151

Earlier quoted context omitted.

Quoted post unavailable.

Unless you're someone's physician you can't really make an assessment that would allow you to determine if someone is intellectually disabled, so don't use it as an insult.

Am I allowed to allege that someone or some act was negligent without being a lawyer? Can I call someone incompetent without performing a study?

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

#152

Earlier quoted context omitted.

What’s the difference? In both the 12 and 24 hour system the clock rolls over at the end of the period, and the period starts.

The difference is that in 12-hour system, the rollover point is ambiguous and non-intuitive (11 PM -> 12 AM -> 1 AM), while in 24-hour one it's perfectly clear and obvious.

I find the 12-hour system as intuitive as the 24-hour system. It is centered around noon, where "AM" means time on the same day before noon, and "PM" means time after, on the same day. Nothing wrong with that.

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

#154

Earlier quoted context omitted.

> you generally pronounce it as military time WTF is 'military time'?

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

Errrrm....

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

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

#155

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…

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> The vast majority of the world uses the metric system for all measurements.

Except for times and angles (only the second and the radian are SI). Also, aviators everywhere outside of PRC and North Korea use feet and flight levels (hundreds of feet) for altitude, and navigators (in the air and at sea) use nautical miles and knots. Other widely used non-metric units include mmHg for pressure, AU and parsec for astronomical distances, and eV for energy.

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

#156

Earlier quoted context omitted.

Quoted post unavailable.

Unless you're someone's physician you can't really make an assessment that would allow you to determine if someone is intellectually disabled, so don't use it as an insult.

No post body was provided.

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

#157

Earlier quoted context omitted.

The difference is that in 12-hour system, the rollover point is ambiguous and non-intuitive (11 PM -> 12 AM -> 1 AM), while in 24-hour one it's perfectly clear and obvious.

I find the 12-hour system as intuitive as the 24-hour system. It is centered around noon, where "AM" means time on the same day before noon, and "PM" means time after, on the same day. Nothing wrong with that.

That's only because you're used to it and have additional context already. The day starts at 12 and goes to 1 an hour later, so notion of "same day" is absolutely ambiguous.

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

#158
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.

No, 12:00:01 AM being a second after noon (i.e. 12:00:01 after the start of the before-noon) is the only one that makes sense. You can't just swap out the reference point and keep counting, that's just as moronic as claiming 1/500 of a dollar is 0.002 cents, because it's in the cents territory. If you want to switch the reference point, you also have to reset the counting to the correct value: 00:00:01 PM = 12:00:01 AM.

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

#159

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…

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It may be ludicrous but at least it's tolerant.

Many Americans would use standard _given the opportunity_. Nothing here was ever converted, or has the same availability in metric so things continue on as they always have. Very few defend them as better, especially distance measurements.

Claiming there is a "better" system for dates is just preference. Why does it make sense to list the year first, it only changes once every 365 days?

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

#160

Earlier quoted context omitted.

What’s the difference? In both the 12 and 24 hour system the clock rolls over at the end of the period, and the period starts.

The difference is that in 12-hour system, the rollover point is ambiguous and non-intuitive (11 PM -> 12 AM -> 1 AM), while in 24-hour one it's perfectly clear and obvious.

The 24 hour system: 23 -> 0 -> 1

How is that different than 11 -> 12 > 1 ?

Yes I get it that in normal integers, 1 is not after 12, but neither is 0 after 23.

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