14 ms·

Ask HN: What does 12:00 AM mean?

• a-dub 5y ago
  i think the moral of the story is that presentation formats for dates and times should follow the end user's locale.
• throwzaway20102 5y ago
• spacec0wb0y 5y ago
  Using 24hr clock. It would have been 00:00 for you.
  • thfuran 5y ago
    Of course, if you list a time as 00:00 for a US audience, you'll probably get a lot of people complaining that it's broken.
    • spaetzleesser 5y ago
      And in the same way it's impossible for the US audience to learn metric it's also impossible for them to learn 24 hr time.
• Quikinterp 5y ago
  A lot of my exams will use the time 11:59pm instead of 12:00am to avoid confusion like this
  • xiphias2 5y ago
    I had the same with travelling, plane times started at 11:59pm.
  • technobabbler 5y ago
    That doesn't help people who don't know what am/pm are. 11:59pm would be 23.59 in some places (like Finland). It's possible to mix up dates and times from each other too (is 12.30 Dec 30 or half past noon?)
    • orev 5y ago
      11:59 pm is 23:59 by all definitions. Why GP would have exams at midnight is anyone’s guess, but the example can only be interpreted as just before midnight.
  • sonicggg 5y ago
    That was common in my university as well, for the same reason. I think OP's school lacked some common sense with the schedule.
    • technobabbler 5y ago
      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.
      • rspoerri 5y ago
        11:59am is 11:59 (in 24h) 11:59pm is 23:59 (in 24h) afaik everywhere... but if i understand it correctly: 12:00pm is 12:00 (in 24h) 12:59pm is 12:59 (in 24h) 01:00pm is 13:00 (in 24h)
      • davidjytang 5y ago
        > The mere use of "11" would suggest morning. No, it does not. We 24ers read clock. 11 doesn't suggest morning.
• BadOakOx 5y ago
  The best is how it is 11AM -> 12PM -> 1PM -> 2PM and then again 11PM -> 12AM -> 1AM -> 2AM
• kuroguro 5y ago
  Obviously you specify a unix timestamp! /s
• tacostakohashi 5y ago
  Do you know what 12:01 AM means? 12:00 AM is one minute before that.
  • EL_Loco 5y ago
    This is only ok as a way to know. The person could then argue "so one minute before 12:00 AM is 11:59 AM, right?" If the person's not familiar with the convention, it makes sense.
  • MD87 5y ago
    But you can also say: "Do you know what 11:59PM means? 12:00PM is one minute after that" Midday and midnight are the points at which AM/PM change and you can't logically differentiate them by appending AM or PM. You just have to know the arbitrary cultural convention that midday is PM.
    • timdiggerm 5y ago
      I think, though, that your example is less convincing, since the hour changes.
    • tacostakohashi 5y ago
      The underlying observation is that the entire hour from X:00 - X:59 is either AM or PM, and not a mixture. 12:00 and 12:01 are both in the 12:XX hour, but 11:59 and 12:00 are not. Of course the whole thing is arbitrary, but the convention is that the 12:00 - 12:59 hour is PM, rather than just 12:00.
  • deleted 5y ago
    [deleted]
  • martin_a 5y ago
    > 12:00 AM is one minute before that. Which is strange, because it does not follow the concept that all other of those time"stamps" do. 12 AM implies that 12 hours of something has passed, but it's nothing that we would align our lives against. And why is 11 AM after 12 AM on the same day? There's no logic (ok, some, but... well... a strange one) behind that.
• dijit 5y ago
  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. Personally I believe that is stupid that we go from 11pm to 12am, but the reason is that the cutover is “12”, and everything after 12 (including the hour) are considered morning. Like others have mentioned, we should really be using 24hr time these days where possible. Additionally I’m of the impression that we should use ISO8601 for date formats instead of what the Uk does (or even worse: what the US does).
  • thanatos519 5y ago
    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.
    • technobabbler 5y ago
      If you can convince my government and my CEO, I'm game!
      • majewsky 5y ago
        I'm propagating the ISO date format with Guerilla tactics. Whenever I come across meeting minutes or documentation pages using a different date format, I silently reformat into ISO date format and then it just catches on. The "normative force of the factual" can be strong.
        • technobabbler 5y ago
          I like this. The guerilla war for universal understanding!
  • hnbad 5y ago
    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 it to be that way ever since digital watches became a thing and people no longer had to rely on bell towers to give them the time of day (which can't strike zero times for obvious reasons).
• jwalton 5y ago
  If 12 is midnight or noon, then 12:00am has to be midnight. If 12:00am was noon, then 12:59am would be in the afternoon, which would be weird. Of course, having your clock start at 12 and then go to 1 is also weird.
• fidgetspinoza 5y ago
  I remember it like this: when it says 12:00 AM that means that the AM is getting started (midnight) and at 12:00 PM the PM is getting started (midday)
• chekibreki 5y ago
  • micromacrofoot 5y ago
    • maydup-nem 5y ago
      • Koshkin 5y ago
        Because some people are born that way.
        • maydup-nem 5y ago
          • micromacrofoot 5y ago
            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.
            • thfuran 5y ago
              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?
              • micromacrofoot 5y ago
                Criticize the act on the merits of the act, but don't use a physical condition as an insult. I don't think it's as hard as you make it out to be. For example, I could say that you're ignorant of the harm that the colloquial use of "retarded" has on disabled people. I could say that you're being needlessly obtuse or selfish by claiming that you should be able to call things "retarded" despite polite requests to stop. I could say that you're callously dismissive of disabled people who are asking for you to stop using the word "retarded" as an insult.
• tomrod 5y ago
  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.
  • Ensorceled 5y ago
    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.
    • tomrod 5y ago
      Future maintainers thank you!
• Sosh101 5y ago
  If a time included either "AM" or "PM" then I would assume it was specified as 12h, not 24h.
• rogual 5y ago
  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.
  • kangalioo 5y ago
    1-based indexing biting us again
  • captainmuon 5y ago
    I would have thought it's AM for the whole of the 12th hour. So 12:00 AM, 12:01 AM, 12:59 AM, 1:00 PM (hour one, past the hour of noon). An hour being a time span of 60 minutes, not an instant! In the "correct" usage, you have an illogical jump between 11:59 AM and 12:00 PM.
    • softwarebeware 5y ago
      Yes this is correct. It can be 12:28am, 12:43am, 12:55am, etc. And it rolls over from 11:59am to 12:00pm.
  • paskozdilar 5y ago
    Why not just call it 00:00:01 PM? And similarly, 00:00:01 AM?
  • c-cube 5y ago
    That is not obvious at all if you're used to the 24h system. If you don't remember which one is 12am, then you don't know if 12h01am is at night or mid day.
  • nilstycho 5y ago
    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.
• rsstack 5y ago
  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 the "quirky Europeans who have to do everything special". But to your question, yes 12:00 AM is midnight. It's the 12 o'clock that's at/after midnight, while 12:00 PM is the 12 o'clock that at/after noon.
  • maydup-nem 5y ago
    > quirky Europeans who have to do everything special so how many quarter inches are the footegg fields these days?
    • Ekaros 5y ago
      The inch breaks down to thirds that is barleycorns, not fourths... And is defined by them...
    • rsstack 5y ago
      34560 eighths, it's easy to remember because it's 3-4-5-6. Divide by two for quarters. Duh. /s
  • wil421 5y ago
    How often does this actually happen? It’s never been common for my European coworkers or my American ones. I rarely schedule meetings with Europe in the Eastern TZ afternoon and the same with India. If I say I’m deploying at 11pm on Saturday everyone understands.
    • rsstack 5y ago
      "Let's meet at your 4pm Tuesday." "The flights for the off-site land on 4/2 at 3pm local time."
• MrRadar 5y ago
  Look at an analog 12-hour clock. Ask yourself what the "natural" way to read it at midnight would be (what number is the hour hand pointing towards)?
  • prmoustache 5y ago
    I don't think it is a usable way to make a european grasp that. Analog clock or not, for all of us 12 is 12 only at noon, otherwise it is 0. The Ante Meridian / Post Meridian explanation works better. Still, it is a fucked way to say time. By the way 24h analog clocks exist too.
    • deleted 5y ago
      [deleted]
• reedf1 5y ago
  I think it makes sense in a world where reading a clock face is common (12 gradations repeating twice is easier to read at a glance than 24 gradations), but in a modern world that is international and the primary timekeeper is a phone, I don't think it is defensible.
• goosedragons 5y ago
  Do Europeans just not have analog clocks or watches anymore?
  • prmoustache 5y ago
    We do but 12 is noon for us, otherwise past 11:59 in the evening it goes back to 0.
    • moralestapia 5y ago
      Do your analog clocks have all numbers from 0-23 in them?
      • prmoustache 5y ago
        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.
  • moralestapia 5y ago
    I also found the "European" remark a bit weird. I'm American so I don't really know, do Europeans generally ignore how AM/PM works? IIRC the Romans created the system, so I'd find it really weird if it had dissapeared from common usage around there. Also, every single picture I've found of a clock tower from Europe seems to follow a 12-hour convention.
    • jaegerma 5y ago
      Even when it's midnight and the clock hands point to 12, it's just 0:00 in our heads. Of course when thinking an talking about time, sometimes the numbers 13 to 23 are replaced with their 1 to 11 counterparts and if it's ambiguous, a "in the morning", "in the afternoon", "in the evening" is added. But there's a clear distinction between "0" and "12". When someone says "12 o'clock", it's always 12 noon and never 12 midnight, since that would be "0 o'clock".
• mauvehaus 5y ago
  The way to remember this that finally clicked for me is that 'A' means 'ante', 'P' means 'post', and 'M' means Meridian some Latin word that means the sun is directly overhead. Or more practically speaking: noon. 12:00 PM is noon because one minute later, the sun is past being directly above. That is, it's 12:01 Post Meridiem. Since it would obviously be nonsensical for 12:00 AM to be immediately followed by 12:01 PM, noon is 12:00 PM by convention. Extending this logic to midnight is left as an exercise to the reader. Don't feel bad, I don't think anybody explained this to me until I was almost 30.
  • martin_a 5y ago
    Does not make any sense at all. You jump from "sun is overhead in 12 hours" (12 AM) to "sun is overhead in 1 hour" (1 AM) when you follow that logic. The 12 hour-system is broken and should go away.
    • Koshkin 5y ago
      Would you want the clock face to be changed to show 24 hours instead of 12? (What would be the number at the top then - 0 or 24?)
      • hnbad 5y ago
        Easy alternative: start the clock at zero like a rational individual would. 12 only makes sense if you see it as the end and go backwards from there. It's a bit like the confusing mess of how year numbers work where traditionally there is no year zero (because the year one is 1 AD, i.e. the first year "of our Lord", i.e. year numbers are actually ordinal even though everyone treats them as nominal). Besides, at this point 90% of the time formats people look at in their daily lives are probably digital (since analog faces are only relevant to actual clocks and even most clocks are likely digital simply because so many electronic devices come with digital clocks) and even analog clocks don't always have numbers on them (or use fanciful alternatives like Roman numerals). The people who prefer analog clocks are clearly just sticking with them out of personal preference or aesthetics anyway.
      • 5y ago
• amalcon 5y ago
  For historical reasons[0], with 12-hour clocks, 12 is generally treated as zero. A general fix for this is probably something like Linux locale settings. It's going to be a rather flawed solution, what with those settings being super complicated. [0]- Lore is that the sundial and dividing the day into 12 sections happened before the invention of the number zero, but I don't know if this is accurate.
• paulcole 5y ago
  > How do we solve this more universally? Use this as an opportunity to realize that moving forward you need to be sure about times — especial for things that really matter. Using your European-ness and the fact that you’re an engineer isn’t an excuse. You can be disappointed in software and other people for the rest of your life and keep missing important appointments if that’s what you want.
• technobabbler 5y ago
  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 even have them), etc. To say nothing of language and cultural differences, just formatting basic facts. You don't solve it "universally", you make affordances for diversity the same way you allow for light/dark mode or language or any other user preference. Not even all calendars have proper embedded time zone information so that's not always reliable either. There is Unix time but you still have to convert that according to arbitrary rules, especially for countries that observe variable daylight savings like the US. It gets even harder when you have to do math, like 00:00 Jan 1 1970 plus 30 years isn't automatically midnight of Jan 1 2000. It depends on whether you mean 30 * 365 24-hour days or some # of quartz vibrations or 30 * orbits around the sun or 30 * years of a certain country's time (adjusted for leap years and leap seconds and daylight savings and time zone changes mandated by new laws). There is no "right" answer. Libraries like Luxon or Momoent can help, but it's never easy. That's just the reality of a multicultural business world. When in doubt, double check and reconfirm.
  • mrsuprawsm 5y ago
    [flagged]
    • technobabbler 5y ago
      Eh, I only said that because I didn't grow up in the US, and had to learn American ways to live and work here. America's a huge part of the world economy and international business, so you're probably going to run into one at some point (sorry, Earth). But the US isn't the only place with different practices. China has no time zones. New Zealand's Chatham Island has a 45 min time zone, as in UTC+12:45. Some institutions use lunar or cultural calendars instead of Gregorian time. Some don't use Arabic numerals outside of Western collaboration. Time aside, the US, Canada, Chile, Colombia, the Philippines, and a few other places use letter-sized instead of A4 paper. Phone number formats are different everywhere. The time and decimal separators are different in many places. Time and timeliness (as in how important it is to start and end on time) differs by culture. Preference for information density vs simplifying cognitive load (in the UX sense) differs between languages and cultures. Red is a warning in some cultures and good luck in others. Not all colors are even distinguishable between cultures. Do you act casual, or formal? Keep your distance or offer a touch? Right hand, left hand? Is pointing OK? How long should you maintain eye contact? First names, last names? Many cultural systems don't identify people like that. Nodding isn't a universal gesture. Do you do a haka before events? What about a ritual blessing before a competition? There are SO many differences to consider in an international context. Big companies have entire departments working on this stuff, not because they are ludicrously US-centric, but because it's so different everywhere. I only mentioned the US vs Europe differences because that's what the OP asked for. Shrug. I'm not shilling for the American ways, just describing them. I wish we went metric decades ago, because it's a far superior system. But the thing about standards: everyone has their own.
• amarshall 5y ago
  There is no universally agreed upon definition. This is why some may use either 12:01 AM or 12:01 PM to avoid ambiguity. Or “12 noon” and “12 midnight”. Of course, the “obvious” answer is to just use 00:00 and 12:00. Lots of folks here are trying to logically determine which use is “correct”, but it doesn’t really matter much if the reader doesn’t agree and misinterprets. So the best option is to use an unambiguous alternative like above. For more, see https://en.wikipedia.org/wiki/12-hour_clock#Confusion_at_noon_and_midnight https://en.wikipedia.org/wiki/12-hour_clock#Confusion_at_noo...
  • akvadrako 5y ago
    Although it's true there are rare exceptions, I've never met a native AM/PM user who thought 12:00 AM was noon.
• SahAssar 5y ago
  I'd be triped up too... to me it makes no sense that it goes 11AM, 12PM, 1PM. That it keeps the number sequence, switches the AM/PM, and then an hour later wraps the number sequence is just odd.
  • goosedragons 5y ago
    It comes from analog clocks and how you read them. They only have 12 hours, so 11:59 ticks over to 12:00.
    • SahAssar 5y ago
      11:59 to 12:00 makes perfect sense. 12:59 to 1:00 makes perfect sense (since it wraps after 12). What does not make sense to me is not switching from AM to PM at the same time as wrapping from 12 to 1. I understand that it comes from analog clocks, but when represented on anything else it feels wrong.
• ju-st 5y ago
  I always look it up on Google. I regularly run into this kind of problem when looking at log files which use AM/PM time. Related question: How do you even say "14:00" in English? In school I learned that you say o'clock but I never heard that in real life.
  • blibble 5y ago
    14:00 -> fourteen hundred hours 14:01 -> fourteen oh one 14:10 -> fourteen ten etc
  • branon 5y ago
    "Fourteen hundred" Fourteen o'clock works too but is less natural.
    • Koshkin 5y ago
      Indeed, “o’clock” is what you say when you look at a clock face!
  • andrewzah 5y ago
    I’ve heard and used “o’clock” my entire life but not with 24 hour time. You could say “fourteen hundred (hours)” or 2 pm/o’clock. For 08:00, “oh 8 hundred hours”.
  • dccoolgai 5y ago
    Over 12, you generally pronounce it as military time. So you would say "14 hundred hours" I think.
    • GoodbyeMrChips 5y ago
      > you generally pronounce it as military time WTF is 'military time'?
      • dccoolgai 5y ago
        https://militaryconnection.com/military-time/amp/ https://militaryconnection.com/military-time/amp/
• sirfrankiecrisp 5y ago
  I remember having the same problem as a Swiss exchange student in high school in the US. I missed a perfect score in my first geography exam there, where we had to calculate timezone, exactly because of this... I thought it was so much more logical to have 12am follow 11am... I was very annoyed to not get 100 in that exam just for such an annoying format... In retrospective it does make sense actually... as soon as you pass noon (meridium) you are in the post-meridian, not ante anymore... Better would be if the formst would use 00:00am and 00:00pm... This way you would have a switch from am to pm and v.v. when the time goes from 11:59 to 0, i stead of to 12.
• Ferrotin 5y ago
  To answer the question: as an American, I learned 12:00 AM was midnight at one point when I was a kid. Before then, I was unsure whether noon was 12 AM or 12 PM. I made sure to remember that special fact, with no mnemonic or rationale, in the future.
• ZetaZero 5y ago
  So as a programmer, one way to look at it, 1:00AM to 12:59AM should be in order, meaning 12:00AM is at noon, and the switch to PM happens at 1PM. But this is wrong. Zero-indexing would have helped here. It really irks me that we stick with these anachronistic standards. 00:00-23:59 seems so much better. Metric system is better. I'm for English-language spelling reform.
• OrangeMonkey 5y ago
  I am native to the united states and, to this day, I still do not fully get what time "12:00 AM" and "12:00 PM" mean. I try to set meetings for 12.01PM. If I absolutely must meet exactly at noon, I start the meeting "at noon".
  • gk1 5y ago
    12PM = Noon 12AM = Midnight
• deleted 5y ago
  [deleted]
• ape4 5y ago
  Say "noon" or "midnight". ya, I know that's cheating.
• akarve 5y ago
  Use a calendar app. It parses and translates appointments into local time as an essential part of its existence.
• keiferski 5y ago
  I always just write 11:59 P.M or 11:59 A.M. to make this less confusing. Especially because the people setting the time are prone to making the same mistake when scheduling the event. For example: ...the discount expires at 11:59 P.M. on Thursday, March 24, 2022. is far less confusing than: ...the discount expires at 12:00 A.M. on Friday, March 25, 2022. At a quick glance, it's easy to think this means late Friday night, since we see the word Friday.
  • technobabbler 5y ago
    This help domestically, but not across cultures that don't use 12 hour time.
    • keiferski 5y ago
      You can always just say 23:59 instead of 12:00 A.M.
      • technobabbler 5y ago
        Believe it or not, some Americans will be confused by that. Our modern educational systems don't really prepare them for international communications. It just depends on your audience & context...
• Koiwai 5y ago
  I guess people solve this by not doing business around that time.
• signal11 5y ago
  The English-language convention I was taught is that 12am is midnight — the rationale I was given was that 02:00:00 is 2am without ambiguity, and 00:00:01 is 12:00:01am without ambiguity, so 00:00:00 gets to be 12am. I have no idea if that’s a good explanation, but it helped contextualise what in the end is a convention. In my personal experience most English-speaking people will either say “midnight” or use the military convention of 00:00 or 24:00 hours. Royal Observatory Greenwich explains it succinctly[1]: > When most people say 12pm, typically they're talking about the middle of the day: 12 noon. When they say 12am, they normally mean 12 midnight. > While most people follow this convention, technically it's not quite right – as you'll see from the definition of am and pm below. To avoid any confusion (and to make sure you arrive on time), it might be best to say 12 noon or 12 midnight instead. US English is similar[2]: > The American Heritage Dictionary of the English Language (Fourth Edition, 2000) has a usage note on this topic: "Strictly speaking, 12 a.m. denotes midnight, and 12 p.m. denotes noon, but there is sufficient confusion over these uses to make it advisable to use 12 noon and 12 midnight where clarity is required." > Many U.S. style guides, and NIST's "Frequently asked questions (FAQ)" web page, recommend that it is clearest if one refers to "noon" or "12:00 noon" and "midnight" or "12:00 midnight" (rather than to "12:00 p.m." and "12:00 a.m."). Some other style guides suggest "12:00 n" for noon and "12:00 m" for midnight. [1] https://www.rmg.co.uk/stories/topics/noon-12-am-or-12-pm https://www.rmg.co.uk/stories/topics/noon-12-am-or-12-pm [2] https://english.stackexchange.com/questions/66633/is-it-correct-to-say-1200am https://english.stackexchange.com/questions/66633/is-it-corr...
• eps 5y ago
  12pm is something that you routinely see in the "day" life - opening/closing times, appointments, etc. That's the one I know. 12am is the other one, so it's at night. I have to deduce every time I see it.
• markus_zhang 5y ago
  In my country we usually say 0:00AM and 12:00 noon (neither am nor pm). After coming to NA I'm gettimg used to 12:00am and 12:00pm. But yeah in the beginning it takes some time.
• hnbad 5y ago
  There's no logic behind this. Even if you go by the reasoning that 12 PM is noon because any time after exactly 12 PM sharp is post-meridian if the meridian is exactly at 12, it shouldn't be 12 but 0. Having an intentional off-by-one error in your date format is simply bad design and counterintuitive. The 12 hour date format with AM/PM is asking for trouble and it's at least partially their fault that you got this wrong, especially if they schedule appointments at unusual times and expect you to find noon and midnight equally reasonable. They could have avoided this easily but their lack of accomodation shows an intentional disregard. If it's any consolation, Pearson is infamous for horrible exam designs, so at least they're not uniquely shitty towards non-Americans.
• helsinkiandrew 5y ago
  It could be worse - before 1805 on a Royal Navy ships PM would come before AM: "Up to late 1805 the Royal Navy used three days: nautical, civil (or "natural"), and astronomical. For example, a nautical day of 10 July, would commence at noon on 9 July civil reckoning and end noon on 10 July civil reckoning, with PM coming before AM. The astronomical day of 10 July, would commence at noon of 10 July civil reckoning and ended at noon on 11 July" https://en.wikipedia.org/wiki/Nautical_time#Nautical_day https://en.wikipedia.org/wiki/Nautical_time#Nautical_day
• Eddy_Viscosity2 5y ago
  Years ago I missed a night international flight because of this. It left at 12:00 am (midnight) Nov.10, but to me that meant at the end of the day so I show up 3 hours early at 9pm on Nov.10, only to find out the flight left 21 hours ago. I should have arrived 9pm Nov.9 to catch the plane at 12:00am which technically was the very start of Nov.10. I've noticed that they no longer post 12:00am as a flight time. Instead it would be listed a few minutes before, like 11:55pm Nov.9.
  • xiwenc 5y ago
    Sorry to hear that. It’s much worse than my missed exam.
• aerojoe23 5y ago
  Did you get to take your test?
  • xiwenc 5y ago
    Nopes, called the pearson vue support and they said will start a case for me. I was 12 hours late and they need proctors. So there was no point to argue. Best case they refund or allow me to reschedule the exam.
• kashyapc 5y ago
  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.
  • howeyc 5y ago
    usually someone would say "half past nine" I'm not sure I've actually heard it your way
  • technobabbler 5y ago
    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.
    • wink 5y ago
      It's very colloquial and very regional but I've heard English speakers say it. The VAST majority only used "half past x" in my experience. Same thing in German though. Usually you only use "drei viertel neun" and "halb neun" (i.e. 8:45 == three quarters nine, and 8:30) but in some regions they say "viertel neun" (quarter nine) for 8:15, but the people not from that region often mishear it as "viertel nach neun" (quarter past nine) because why would you say the former, so the speaker must have spoke the 'nach' too silent...
  • pieter_mj 5y ago
    I don't think any English speaking person, in whatever variant, would use that expression. What "half negen" means is easier to remember when you contrast "half" to "vol"/"heel" -> half nine is not full nine yet. To be clear, nobody uses "vol negen" or "heel negen", it's just "negen (uur)".
    • 5y ago
• softwarebeware 5y ago
  This is actually a great post about UX. Most sites like eBay or Expedia have location-specific versions that change dates and times among other things to the user’s format. It’s totally legit to expect that in 2022. That said, UTC is universal also.
• njkleiner 5y ago
  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 adopt to local customs". But that would imply the exam takes place on midnight in local time. Is that actually a thing? Like, is this normal? Why on earth would anyone assume that's the case in an ambiguous situation like this, I can see why you would assume it's at noon without giving it too much thought. The second case is that OP not in the same place (e.g. the given time at midnight does not match OP's local time), but in this case I blame the institution for allowing people to attend exams remotely while not properly accommodating for time differences. While 12:00 AM/PM may be technically valid time descriptions, I was under the impression that it was common (in places that use the 12 hour system) to instead write 12:00 noon/midnight specifically to avoid this. From what I understand, Americans are confused by this too, so why are people so eager to blame Europeans, rather than the system? Second, I don't understand people saying they use 11:59/12:01 AM/PM as a mnemonic. This makes no sense to me as 00:01 a valid time. How do the above times resolve anything, when all you do is increase/decrease the time, relative to the label, which is what makes it confusing in the first place. I don't understand how I'm supposed to know which of AM/PM 00:01 refers to, unless I already know what AM/PM means. Third, people making comparisons to reading an analog clock. When I read an analog clock, I get a time in a 12 hour window. Fair enough. But when I then translate it to 24h, what I do is use my knowledge of whether it is currently day or night to translate it. Which has nothing to do with memorizing which label is which. Analog clocks don't have AM/PM labels so how would this make any more sense?
  • technobabbler 5y ago
    Not the OP, just offering some thoughts. > There are two possible cases here. (snip) I was under the impression that it was common (in places that use the 12 hour system) to instead write 12:00 noon/midnight specifically to avoid this. IMHO the bigger takeaway ought to be that what is "common" in your area isn't necessarily common in another part of the country, or in another country. This confusion exists because the Europeans (and nowadays the Americans) exported their time measurement system across cultures, to mixed success. It's never obvious and should not be assumed to be... that confusion can exist no matter what actual UNIX time the test was scheduled at. > Second, I don't understand people saying they use 11:59/12:01 AM/PM as a mnemonic. This makes no sense to me as 00:01 a valid time. For this specific case, it helps clarify what is "noon" vs "midnight". For some reason people are a lot better with knowing 11:59pm is, vs 12:00AM. The cutover is what throws people off. And for most purposes, the +/- 1-3 minute difference won't matter. The midnight/noon thing doesn't really help when you're going across oceans though. Or, like you said, if you're not familiar with AM/PM at all.
• mhogomchungu 5y ago
  Each african here and in Swahili time, the day starts at 7:00 AM and ends at 6:59PM and night starts at 7:00 PM and ends at 6:59AM. So, I would read "12:00 AM" as "six hours into the night" since its been 6 hours since the night has started. I would also read "12:00 PM" as "six hours into the day" since its been six hours since the day has started. Speaking it, i would say "saa 6 mchana" and the literal translation is "time 6 noon". I and most people here always set time in AM/PM format and i always have to first convert it to swahili time before making sense of it.
  • technobabbler 5y ago
    That's really fascinating. When do businesses typically open and close? Are there set times?
    • mhogomchungu 5y ago
      Typically, its from "8:00 AM" to "4:00 PM". In swahili time, i would say "its from hour 2 in the morning to hour 10 in the everning.
• DonaldFisk 5y ago
  Yes. I wish people would stop using that, as it confuses me, just as it confused you. AM = ante meridiem, before noon. PM = post meridiem, after noon. It makes no sense to say midday (meridies in Latin) is before noon or after noon, it's exactly at noon. If you're going to use a 12 hour clock, to avoid confusion, you should write "12 noon" or "12 midnight". That way the confusion is avoided. Alternatively, switch to a 24 hour clock, and if it's international use UTC. And if you can't do that, start your event a minute later: 12:01pm is unambiguously one minute after noon.
  • anotherevan 5y ago
    We did something similar here in Victoria, Australia in the last two years. When there were rule changes around COVID, lock-downs, etc, they would often go into effect at 11:59pm. We typically use twelve hour with am/pm time representations, but I figure the thinking was it would cause less confusion in those anxious times.
• tsujp 5y ago
  12 AM is midnight. 12 PM is noon.
• Yosemite_Sam 5y ago
  If something that I can't miss is listed in a different time zone than the one I'm in I go online and find a time zone converter. You can just tell it '12am in x city' and there is another box where you enter your own location and it doesn all the work for you.
• beej71 5y ago
  For a mathy approach for programmer types, let's switch to decimal hours for a moment. So 12.0 noon is a time, and 12.99 PM is just shy of 1.0 PM. So is midday AM or PM? I think we can agree that 30 minutes after noon, or 12.5, is PM. And we probably also agree that 12.1 would be PM as well. And 12.0001, that's PM. We can put as many zeros in there as we want, and it's still PM. Now put infinity zeroes in there, and you're "at" 12:00 (since that's what the clock now reads) and it's still PM. A shorthand version of this is if you look at the clock in the middle of the day and it says 12:00, is it exactly 12:00 that very instant? Or is it, infinitely more probably, a little bit past that time? If you know it's a little past 12:00, you know if it's AM or PM. As for how to fix it, either "noon"/"midnight" or universal 24-hour clocks or memorize that noon is 12 PM. :)
• TrianguloY 5y ago
  12 is 0, that's how analog clocks display time, and that's the only way to make sense of the strange numbering (12->1->2-...>11? What?). Maybe because Romans didn't have 0? Apparently not, the reason comes from before them, but analog clocks are commonly written with Roman numerals so it's a way to remember this.
• dudul 5y ago
  Sorry it happened to you. Yes it would have been better for this institution to send a true calendar event or something that would adapt to each person's local TZ. That being said, I just googled "12.00 AM" and the very first result is "12.00 AM is midnight". Pretty unambiguous. If you had never seen this notation before, being an engineer, why didn't you just look it up?
• Markoff 5y ago
  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
• KolenCh 5y ago
  A classic problem similar to this would be a flight. If you got a flight departing at 12:40am, make sure you really know what it means. There’s too many people making this mistakes and sometimes the airline might help you out but not always.
  • rexf 5y ago
    That's a good point, but 12:40am is a very unusual flight time? That's almost 1am. I would guess most flights are in the ballpark of 7am - 9pm. Please correct me if I'm wrong.
    • KolenCh 5y ago
      I personally have taken flights with weird departure time like this. A lot of flights from San Francisco to Hong Kong has departure time like this, arriving Hong Kong at around 7am. I think in general it is just depends on the origin+destination time zone & fight duration, these 2 factors determines the sweet spots of departing, and while there can be a few combinations that works, those few combinations can likely be realized due to various factors. Other examples involved going from Hong Kong to London (which has similar relation comparing to going from SFO to HKG). I personally didn’t try that but first heard people made mistake like this (getting to the flight one day late) in this combination.
• rexf 5y ago
  12a vs 12p is pretty confusing. Appending noon or midnight is super helpful in calendar apps. E.g., "12p (noon)" or "12a (midnight)" Self plug: I built a super simple visualization page to help figure out which is which https://xta.github.io/am-pm-visualized/ https://xta.github.io/am-pm-visualized/
• xiwenc 5y ago
  I’m baffled to see those in favor of AM/PM notation fail to acknowledge there is a better, less confusing, alternative. Can we call this “technical” debt? I really like the idea of saying 11:59PM instead. Despite feeling like a duck tape solution. What bothers me more is that internet companies offer services to the global consumer. These services should work for the customer. Not force some cultural or demographic habit on global population. Instead, use non-ambiguous notation like 24h or express noon/midnight explicitly.
• xiwenc 5y ago
  Op here. Update from Pearson Vue: they refunded the exam price.