3 ms·

> Saying "local time" implies all of the above. It means that something is being specified according to the local convention of timekeeping. No, it really does

by amluto 3y ago

> Saying "local time" implies all of the above. It means that something is being specified according to the local convention of timekeeping. No, it really doesn’t. Saying “4pm at the coffee shop” means that, and this is a big distinction. If I’m in a different time zone two days before the meeting, looking at my calendar, I sure hope my calendar understands the difference. If I move my entire home outside the timezone, the appointment doesn’t magically shift an hour as a result. And any decent time library can handle this just fine as long as you don’t use “local” time. Just specify the actual timezone!

lijok 3y ago
Unfortunately timezones have the nasty ability to change. See: https://codeblog.jonskeet.uk/2019/03/27/storing-utc-is-not-a-silver-bullet/ https://codeblog.jonskeet.uk/2019/03/27/storing-utc-is-not-a...
- Hackbraten 3y ago
  That's why they wrote "state the actual timezone" and not "state the actual UTC offset." Actual timezone would mean "2025-01-01 16:00:00 Europe/Berlin," not just "2025-01-01 16:00:00 +01:00."
  - lijok 3y ago
    Even those change
    - Hackbraten 3y ago
      I agree. The city where the cafe is located might be annexed or usurped by another country, and have another timezone imposed on it. Handling that kind of change would be beyond impractical though?
      - lijok 3y ago
        Good question. I wonder what impact timezone wise the annexation of Crimea had on hypergiants like FAANG. I can imagine some weirdness when rerunning say historical domain events to hydrate a new service. Wonder if they have libraries to handle such edgecases
MereInterest 3y ago
> No, it really doesn’t. Saying “4pm at the coffee shop” means that, and this is a big distinction. Some words and phrases, such as "4 pm local time", require some of their semantic meaning to be inferred from context. This doesn't mean that they are meaningless. It means that the relevant context must be provided in order to interpret the phrase. If you and I have been scheduling the coffee shop meetup, then the phrases "4pm", "4pm local time", and "4pm as measured by the applicable standards in the area of the coffee shop on the day of the meeting" are all equivalent. > Just specify the actual timezone! This is the problem that I pointed out. The appropriate context for "4pm local time" is "at the coffee shop". However, most calendar programs will only let you provide context such as "Eastern Standard Time". This is the wrong context altogether, and choosing it assumes that the area will have extended the duration of DST between time of scheduling and time of meeting.
- amluto 3y ago
  > Some words and phrases, such as "4 pm local time", require some of their semantic meaning to be inferred from context. This doesn't mean that they are meaningless. It means that the relevant context must be provided in order to interpret the phrase. This is not what the proposed LocalDateTime would do. This is a “naive” time, and those are only really useful for calendar math or when you want to apply a concrete timezone.

by amluto 3y ago

lijok 3y ago

Unfortunately timezones have the nasty ability to change. See: https://codeblog.jonskeet.uk/2019/03/27/storing-utc-is-not-a-silver-bullet/ https://codeblog.jonskeet.uk/2019/03/27/storing-utc-is-not-a...

Hackbraten 3y ago
That's why they wrote "state the actual timezone" and not "state the actual UTC offset." Actual timezone would mean "2025-01-01 16:00:00 Europe/Berlin," not just "2025-01-01 16:00:00 +01:00."
- lijok 3y ago
  Even those change
  - Hackbraten 3y ago
    I agree. The city where the cafe is located might be annexed or usurped by another country, and have another timezone imposed on it. Handling that kind of change would be beyond impractical though?
    - lijok 3y ago
      Good question. I wonder what impact timezone wise the annexation of Crimea had on hypergiants like FAANG. I can imagine some weirdness when rerunning say historical domain events to hydrate a new service. Wonder if they have libraries to handle such edgecases

MereInterest 3y ago

> No, it really doesn’t. Saying “4pm at the coffee shop” means that, and this is a big distinction. Some words and phrases, such as "4 pm local time", require some of their semantic meaning to be inferred from context. This doesn't mean that they are meaningless. It means that the relevant context must be provided in order to interpret the phrase. If you and I have been scheduling the coffee shop meetup, then the phrases "4pm", "4pm local time", and "4pm as measured by the applicable standards in the area of the coffee shop on the day of the meeting" are all equivalent. > Just specify the actual timezone! This is the problem that I pointed out. The appropriate context for "4pm local time" is "at the coffee shop". However, most calendar programs will only let you provide context such as "Eastern Standard Time". This is the wrong context altogether, and choosing it assumes that the area will have extended the duration of DST between time of scheduling and time of meeting.

amluto 3y ago
> Some words and phrases, such as "4 pm local time", require some of their semantic meaning to be inferred from context. This doesn't mean that they are meaningless. It means that the relevant context must be provided in order to interpret the phrase. This is not what the proposed LocalDateTime would do. This is a “naive” time, and those are only really useful for calendar math or when you want to apply a concrete timezone.