5 ms·

It’s difficult to maintain basic features in a popular calendar, at least according to the ms exchange team blog: > calendaring is particularly tricky. Why’s t

by thih9 2y ago

It’s difficult to maintain basic features in a popular calendar, at least according to the ms exchange team blog: > calendaring is particularly tricky. Why’s that? Well, consider time zones for a start – a meeting you set up isn’t necessarily in the same time as it is for me, and then you also invited people, from a whole bunch of other time zones (did you know some time zones are 30 mins off, not a full hour?) (…) https://techcommunity.microsoft.com/blog/exchange/calendaring-is-really-hard-to-code-and-that%E2%80%99s-why-you-were-an-hour-late-to-that-/1165583 https://techcommunity.microsoft.com/blog/exchange/calendarin... Then there is the “falsehoods programmers believe about time” list: https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b... , with some counter examples: http://www.creativedeletion.com/2015/01/28/falsehoods-programmers-date-time-zones.html http://www.creativedeletion.com/2015/01/28/falsehoods-progra...

karamanolev 2y ago
Eh, I don't buy that. Storage in UTC and converting to a local timezone for display / notification purposes has been the standard practice for a looong time. What I would believe, I don't know if true, is that different applications support subtly different feature sets, integration has varying levels of support and correctness and so on. Additionally, I feel like vendors are incentivized to offer good support within their ecosystem, but integration with the outside world is a second-class citizen.
- pluies 2y ago
  > Storage in UTC and converting to a local timezone for display / notification purposes has been the standard practice for a looong time. All good until summer time kicks in and your recurring 9am meeting now starts at 8am, oops.
  - haakonhr 2y ago
    But summertime is a (at least here) a separate timezone, e.g., CET vs CEST
    - ivan_gammel 2y ago
      Timezones change.
    - deleted 2y ago
      [deleted]
    - happytoexplain 2y ago
      The point is that humans want a meeting's clock time to change when they travel to a new time zone, but not when their local time changes (either due to DST or a legal change). Unless of course not everybody invited shares the same DST patterns, in which case it has to change for some of the participants (how do you choose which?). Also, the relationship between the datetime the user chose and the UTC time you store can be retroactively changed by legislation.
- ivan_gammel 2y ago
  Storage in UTC is generally wrong for future events and doesn’t make sense at all for unbounded sequences. Edit: better approach will be to store event as it was defined and include processing hints, e.g. when next UTC time of occurrence can be reliably established.
- makeitdouble 2y ago
  UTC storage is standard practice, but not the best practice nor something that solves all the major issues a good application should be dealing with. I'd qualify it as "good enough to not get fired" grade of decision, for people who don't care that much about calendaring in the first place or have the luxury ignore complex cases (we're back to "why are calendars so hard?")
- happytoexplain 2y ago
  "Just store it in UTC" will cause bugs for human time, which calendaring is the most complex example of (because it contains basically every other use case). Don't throw away the date and time the user entered. How you store it is the subjective part, as different choices have different risks. But don't just throw it away. Also, the existence of this thread should be good evidence that it is indeed not that simple.
ivan_gammel 2y ago
Timezone stuff is trivial with modern libraries like Java Time API. Event entity and event identity is hard.
godelski 2y ago
I don't buy it. I do think the problems are not trivial but it's not like there aren't trivial problems within the larger problem. Let's take a trivial problem: holidays. Every account you have comes with a holiday calendar. So if you got a Microsoft, Google, and Apple account you'll have entries in triplicate. These are all day events with identical names. There's a lot of hints to tell you that these are identical and you only need to display 1. A bit harder would be birthdays. These might not be in a unique calendar. But the word "birthday" is a huge hint when it's an all day event. I do agree that defaulting to a position of not destroying data is best (though here we'd never destroy data). But that doesn't mean we can't offer users assistance. We do have the capacity to let users merge events or in some way note that they are identical. One more issue, why the fuck can't I move an event from my Google calendar to my Apple? In the worst case, just copy the damn thing and then hide the event. You can do this even when you don't have write access to the Google calendar. So the thing I don't buy is that we can't do more. A programmer's job isn't easy. But it involves problem solving. I think there's not enough grumpy yet motivated people who will voice up such things because management usually says that it's not important. But these non important things add up. Life is complex so the little things actually matter a lot.
- OptionOfT 2y ago
  Weirdly enough an all day event in Office 365 isn't an all day event on a day. E.g, I record my wife's birthday in my calendar. I create an event on April 12th, and mark it as an all day event. What actually happens is that the calendar records an event that starts at midnight, and ends 24 hours later, and is marked as an all day event. But, when you change timezones the 24 hours actually shift, which can be very weird when you get notifications that are 6 hours earlier.
  - godelski 2y ago
    Sounds like something that could be solved by a flag. if all_day_event: show_option("timezone invariant") If it is timezone invariant, then you can make it the 24hr (or whatever because there might not be 24 hrs in a day...) period relative to the current timezone. This isn't an unsolvable problem, it is just people not seeking solutions. I have a theory: a lot of tech products suck today because either: - People are not dogfooding[0] (using their own products) - People are not raising concerns - People raise concerns but issues are de-prioritized in favor of more flashy things. None of these things are great and they can only happen while a company has significant marketshare and monopoly like status. In essence, it is internal rot. Someone (plural) is disconnected from the actual product. They are out of touch with what the users want. And I mean here's the thing. I could go ahead and write a wrapper for all of this and wrap in all my calendars. But that's a ton of work, there's probably no market, but if there was a market then the realistic result is that my success would result in the big players implementing the same feature and thus devaluing my work even though I increased the value of theirs. So I can do this as an open source project, but boy are there a lot of other higher priority issues like this. The real problem is that these issues can't be resolved within these big companies. For whatever reason that is, it is bad business. [0] https://en.wikipedia.org/wiki/Eating_your_own_dog_food https://en.wikipedia.org/wiki/Eating_your_own_dog_food
TeMPOraL 2y ago
> It’s difficult to maintain basic features in a popular calendar, at least according to the ms exchange team blog: There's a large amount of things that regular people do with calendars every day, that could be automated or managed through better interaction paradigms, and to which those issues don't apply. That's a lot of low hanging fruits, that everyone's leaving to rot. Like: > meeting you set up isn’t necessarily in the same time as it is for me, and then you also invited people, from a whole bunch of other time zones (did you know some time zones are 30 mins off, not a full hour?) 99% of my calendar use involves events happening within days or weeks, and concerning me alone, me and my wife, me and my acquaintances, or me and some random local company. I don't care about timezones for those - they all happen in the same one, with the same DST shift. (The remaining 1%? Timezone shenanigans happen at few distinct points in a year, and everyone knows to be careful around those and communicate out-of-band if needed. So again, not an issue in practice for users like me.) Microsoft is thinking about calendars as tools for employees of multinational corporations. But calendars aren't only useful for managers frequently flying intercontinental; there's a lot of regular folks using them for affairs much more localized in time, space, and social graph.

by thih9 2y ago

karamanolev 2y ago

Eh, I don't buy that. Storage in UTC and converting to a local timezone for display / notification purposes has been the standard practice for a looong time. What I would believe, I don't know if true, is that different applications support subtly different feature sets, integration has varying levels of support and correctness and so on. Additionally, I feel like vendors are incentivized to offer good support within their ecosystem, but integration with the outside world is a second-class citizen.

pluies 2y ago
> Storage in UTC and converting to a local timezone for display / notification purposes has been the standard practice for a looong time. All good until summer time kicks in and your recurring 9am meeting now starts at 8am, oops.
- haakonhr 2y ago
  But summertime is a (at least here) a separate timezone, e.g., CET vs CEST
  - ivan_gammel 2y ago
    Timezones change.
  - deleted 2y ago
    [deleted]
  - happytoexplain 2y ago
    The point is that humans want a meeting's clock time to change when they travel to a new time zone, but not when their local time changes (either due to DST or a legal change). Unless of course not everybody invited shares the same DST patterns, in which case it has to change for some of the participants (how do you choose which?). Also, the relationship between the datetime the user chose and the UTC time you store can be retroactively changed by legislation.
ivan_gammel 2y ago
Storage in UTC is generally wrong for future events and doesn’t make sense at all for unbounded sequences. Edit: better approach will be to store event as it was defined and include processing hints, e.g. when next UTC time of occurrence can be reliably established.
makeitdouble 2y ago
UTC storage is standard practice, but not the best practice nor something that solves all the major issues a good application should be dealing with. I'd qualify it as "good enough to not get fired" grade of decision, for people who don't care that much about calendaring in the first place or have the luxury ignore complex cases (we're back to "why are calendars so hard?")
happytoexplain 2y ago
"Just store it in UTC" will cause bugs for human time, which calendaring is the most complex example of (because it contains basically every other use case). Don't throw away the date and time the user entered. How you store it is the subjective part, as different choices have different risks. But don't just throw it away. Also, the existence of this thread should be good evidence that it is indeed not that simple.

ivan_gammel 2y ago

Timezone stuff is trivial with modern libraries like Java Time API. Event entity and event identity is hard.

godelski 2y ago

I don't buy it. I do think the problems are not trivial but it's not like there aren't trivial problems within the larger problem. Let's take a trivial problem: holidays. Every account you have comes with a holiday calendar. So if you got a Microsoft, Google, and Apple account you'll have entries in triplicate. These are all day events with identical names. There's a lot of hints to tell you that these are identical and you only need to display 1. A bit harder would be birthdays. These might not be in a unique calendar. But the word "birthday" is a huge hint when it's an all day event. I do agree that defaulting to a position of not destroying data is best (though here we'd never destroy data). But that doesn't mean we can't offer users assistance. We do have the capacity to let users merge events or in some way note that they are identical. One more issue, why the fuck can't I move an event from my Google calendar to my Apple? In the worst case, just copy the damn thing and then hide the event. You can do this even when you don't have write access to the Google calendar. So the thing I don't buy is that we can't do more. A programmer's job isn't easy. But it involves problem solving. I think there's not enough grumpy yet motivated people who will voice up such things because management usually says that it's not important. But these non important things add up. Life is complex so the little things actually matter a lot.

OptionOfT 2y ago
Weirdly enough an all day event in Office 365 isn't an all day event on a day. E.g, I record my wife's birthday in my calendar. I create an event on April 12th, and mark it as an all day event. What actually happens is that the calendar records an event that starts at midnight, and ends 24 hours later, and is marked as an all day event. But, when you change timezones the 24 hours actually shift, which can be very weird when you get notifications that are 6 hours earlier.
- godelski 2y ago
  Sounds like something that could be solved by a flag. if all_day_event: show_option("timezone invariant") If it is timezone invariant, then you can make it the 24hr (or whatever because there might not be 24 hrs in a day...) period relative to the current timezone. This isn't an unsolvable problem, it is just people not seeking solutions. I have a theory: a lot of tech products suck today because either: - People are not dogfooding[0] (using their own products) - People are not raising concerns - People raise concerns but issues are de-prioritized in favor of more flashy things. None of these things are great and they can only happen while a company has significant marketshare and monopoly like status. In essence, it is internal rot. Someone (plural) is disconnected from the actual product. They are out of touch with what the users want. And I mean here's the thing. I could go ahead and write a wrapper for all of this and wrap in all my calendars. But that's a ton of work, there's probably no market, but if there was a market then the realistic result is that my success would result in the big players implementing the same feature and thus devaluing my work even though I increased the value of theirs. So I can do this as an open source project, but boy are there a lot of other higher priority issues like this. The real problem is that these issues can't be resolved within these big companies. For whatever reason that is, it is bad business. [0] https://en.wikipedia.org/wiki/Eating_your_own_dog_food https://en.wikipedia.org/wiki/Eating_your_own_dog_food

TeMPOraL 2y ago

> It’s difficult to maintain basic features in a popular calendar, at least according to the ms exchange team blog: There's a large amount of things that regular people do with calendars every day, that could be automated or managed through better interaction paradigms, and to which those issues don't apply. That's a lot of low hanging fruits, that everyone's leaving to rot. Like: > meeting you set up isn’t necessarily in the same time as it is for me, and then you also invited people, from a whole bunch of other time zones (did you know some time zones are 30 mins off, not a full hour?) 99% of my calendar use involves events happening within days or weeks, and concerning me alone, me and my wife, me and my acquaintances, or me and some random local company. I don't care about timezones for those - they all happen in the same one, with the same DST shift. (The remaining 1%? Timezone shenanigans happen at few distinct points in a year, and everyone knows to be careful around those and communicate out-of-band if needed. So again, not an issue in practice for users like me.) Microsoft is thinking about calendars as tools for employees of multinational corporations. But calendars aren't only useful for managers frequently flying intercontinental; there's a lot of regular folks using them for affairs much more localized in time, space, and social graph.