4 ms·

There are, but we just skip the AM/PM part most of time, because it's obvious from context which one you mean. And if it's not you'll just say "... in the morni

There are, but we just skip the AM/PM part most of time, because it's obvious from context which one you mean. And if it's not you'll just say "... in the morning/afternoon/evening"

tomrod 3y ago
AM: morning, PM: afternoon/evening
- tgaj 3y ago
  Yeah, but this is the problem - why noon is "afternoon"?
  - xen0 3y ago
    "12:00:00 + ε" is after noon, but your clock will not show a difference.
  - tomrod 3y ago
    Clopen intervals in order to have a well-specified time system. [0] [12:00 PM, 12:00 AM) for after the noon instant [1] [12:00 AM, 12:00 PM) for before the noon instant 24-hour time is superior to the mod-12 time system in almost every way but mechanical clock faces and soldier shifts under early systems that used sun dials. However, the equivalent question can be asked by a day is a clopen interval of [00:00 current day, 00:00 next day)
    - eesmith 3y ago
      In 24-hour time, those are 12-24 and 0-12, respectively. https://en.wikipedia.org/wiki/ISO_8601 https://en.wikipedia.org/wiki/ISO_8601 A place open 24 hours/day is open in the period 0-24.
      - tomrod 3y ago
        I don't follow your point. Are you correcting my point on clopen intervals and mod bases?
        eesmith 3y ago
        I think clopen is too complicated in that it expresses ranges that are not practically useful, like (10,11], and it complicates expressing something like "Open 0-24", where your notation appears to require a date. I think you get the essential utility you want in a 24 hour clock by simply letting 24 (or "24:00:00" when fully written out) be a way to represent the end of the day. It's also already in use, with examples at https://ioi2023.hu/faq/ https://ioi2023.hu/faq/ , http://www.garageferrarimilazzo.com/en/ http://www.garageferrarimilazzo.com/en/ , and https://jozsefvaros.hu/english/news-in-the-district/2022/12/public-toilets-in-jozsefvaros/ https://jozsefvaros.hu/english/news-in-the-district/2022/12/... .
  - yjftsjthsd-h 3y ago
    Noon isn't really before or after noon, but we want to lump it together with one of them, so we picked the one that made 12:00 and 12:01 go together. (Edit: or for that matter, 12:00:00 and 12:00:01, down to arbitrary closeness, as sibling comment points out)

There are, but we just skip the AM/PM part most of time, because it's obvious from context which one you mean. And if it's not you'll just say "... in the morning/afternoon/evening"

tomrod 3y ago

AM: morning, PM: afternoon/evening

tgaj 3y ago
Yeah, but this is the problem - why noon is "afternoon"?
- xen0 3y ago
  "12:00:00 + ε" is after noon, but your clock will not show a difference.
- tomrod 3y ago
  Clopen intervals in order to have a well-specified time system. [0] [12:00 PM, 12:00 AM) for after the noon instant [1] [12:00 AM, 12:00 PM) for before the noon instant 24-hour time is superior to the mod-12 time system in almost every way but mechanical clock faces and soldier shifts under early systems that used sun dials. However, the equivalent question can be asked by a day is a clopen interval of [00:00 current day, 00:00 next day)
  - eesmith 3y ago
    In 24-hour time, those are 12-24 and 0-12, respectively. https://en.wikipedia.org/wiki/ISO_8601 https://en.wikipedia.org/wiki/ISO_8601 A place open 24 hours/day is open in the period 0-24.
    - tomrod 3y ago
      I don't follow your point. Are you correcting my point on clopen intervals and mod bases?
      - eesmith 3y ago
        I think clopen is too complicated in that it expresses ranges that are not practically useful, like (10,11], and it complicates expressing something like "Open 0-24", where your notation appears to require a date. I think you get the essential utility you want in a 24 hour clock by simply letting 24 (or "24:00:00" when fully written out) be a way to represent the end of the day. It's also already in use, with examples at https://ioi2023.hu/faq/ https://ioi2023.hu/faq/ , http://www.garageferrarimilazzo.com/en/ http://www.garageferrarimilazzo.com/en/ , and https://jozsefvaros.hu/english/news-in-the-district/2022/12/public-toilets-in-jozsefvaros/ https://jozsefvaros.hu/english/news-in-the-district/2022/12/... .
- yjftsjthsd-h 3y ago
  Noon isn't really before or after noon, but we want to lump it together with one of them, so we picked the one that made 12:00 and 12:01 go together. (Edit: or for that matter, 12:00:00 and 12:00:01, down to arbitrary closeness, as sibling comment points out)