<div dir="auto">then again, what about month numbering in Chinese calendar? There are no month name, only lunar month 1, lunar month 2, etc.</div><br><div class="gmail_quote"><div dir="ltr">在 2019年5月22日週三 20:33，Paul Allen <<a href="mailto:pla16021@gmail.com">pla16021@gmail.com</a>> 寫道：<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div dir="ltr">On Wed, 22 May 2019 at 09:16, Rory McCann <<a href="mailto:rory@technomancy.org" target="_blank" rel="noreferrer">rory@technomancy.org</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
I don't know much about the islamic calendar. Could you give some <br>
examples of what data you'd like to enter? Most "opening hours" don't <br>
need to include years, so is that a problem? You could just use the <br>
islamic calendar month names if needed.<br></blockquote><div><br></div><div>The problem with that is the same problem as allowing every language on the planet to</div><div>use their own abbreviations for month names. Only worse.</div><div><br></div><div>For better or worse, we standardized on three-letter abbreviations for English month names. We</div><div>couldn't have gotten away with one- or two-letter abbreviations because then there would have been</div><div>collisions: "M" could be March or May, "Ma" could be March or May, etc. Allow abbreviations in</div><div>other languages using the Latin alphabet and you get collisions even with three-letter</div><div>abbreviations. So we use English abbreviations, applications are free to translate them</div><div>into the user's own language.<br></div><div><br></div><div>The problem is possibly fixable by switching to month numbering. It doesn't make the translation</div><div>aspect much easier since most modern programming languages can handle hashes (aka</div><div>dictionaries, aka associative arrays) so there's no gain there. It makes human comprehension</div><div>harder, because many people have difficulty mentally translating month 8 to August, so there's</div><div>a disadvantage there (for those with English as a first language; for others it would probably</div><div>be an advantage. It would require editor support (not impossible) and a mass edit of</div><div>the database (not impossible, especially as there's a guaranteed one-to-one correspondence).</div><div>I don't see OSM making the switch to numeric months, because it's a lot of change for little</div><div>gain, but I could be wrong.<br></div><div><br></div><div>Now we throw in the Islamic calendar. Which is luni-solar. It's based around the phases of the</div><div>moon, and there is not a one-to-one correspondence you get between, say, December and the</div><div>Welsh Rhagfyr. In the Islamic calendar, each month can be 29 or 30 days long, depending upon</div><div> the visibility of the moon. Except for the Shia Ismali Muslims, where odd-numbered months have</div><div> 30 days and even months have 29 days. I've neglected leap year handling for simplicity. Then</div><div> there's the Judaic calendar, which is similar in some ways to the Shia Islamic one, except it <br></div><div>is prone to fiddling month lengths to avoid holy days falling on certain days of the week.</div><div><br></div>Is this a real problem? MARchesvan in the Judaic calendar is a collision with MARch, so we'd</div><div class="gmail_quote">have to switch to 6-letter abbreviations. The Islamic calendar has Rabi-Al-Awwal and</div><div class="gmail_quote">Rabi-Al-Thani; Jumada-Al-Awwal and Jumada-Al-Thani; Zul-Qaadah and Zul-Hijjah, so that</div><div class="gmail_quote">would need some though (are RAA, RAT, JAA, JAT, ZUQ ZUH acceptable?). Or we switch to</div><div class="gmail_quote"> month numbers, remembering that Julian month 6 is not Islamic month 6 or Judaic month 6</div><div class="gmail_quote"> and that Shia Islamic month 6 isn't (quite) Judaic month 6 and that you have no idea which</div><div class="gmail_quote"> calendar is in use, just that it's month 6 in some unspecified calendar.<br></div><div class="gmail_quote"><br></div><div class="gmail_quote">There are other calendar systems out there. Parts of the world still use the Julian calendar,</div><div class="gmail_quote">which is currently 13 days ahead of the Gregorian calendar.<br></div><div class="gmail_quote"><br></div><div class="gmail_quote">As others have pointed out, we might be able to accommodate holidays. Although we're likely</div><div class="gmail_quote">to end up with collisions in the two-character namespace we currently allow for them. Feasible,</div><div class="gmail_quote">maybe. Month names are something that isn't feasible without namespacing opening_hours.<br></div><div class="gmail_quote"><br></div><div class="gmail_quote">Oh, and then there's the fact that days start at midnight in the Gregoran calendar but start at</div><div class="gmail_quote">sundown in Islamic and Judaic calendars. And some countries are on solar time, which</div><div class="gmail_quote">can be up to 14 minutes behind or 16 minutes ahead of local mean time. Right now we</div><div class="gmail_quote">assume that times are in the local timezone and that the timezone is offset by a known amount</div><div class="gmail_quote">(usually a multiple of one hour, sometimes a multiple of 30 minutes or even a multiiple of</div><div class="gmail_quote">15 minutes) from UTC, not that local time drifts around. If people want to specify times as</div><div class="gmail_quote">solar time, because that's what their country uses, we again need to namespace</div><div class="gmail_quote">opening_hours.</div><div class="gmail_quote"><br></div><div class="gmail_quote">And don't forget that whatever we come up with has to work in conditional statements. So we</div><div class="gmail_quote">can have major changes to opening_hours that will require support in editors and applications</div><div class="gmail_quote">and will probably have problems that we only discover down the line or we namespace the</div><div class="gmail_quote">opening_hours to keep things simple and to prevent a problem in one affecting all of them.<br></div><div class="gmail_quote"><br></div><div class="gmail_quote">-- <br></div><div class="gmail_quote">Paul</div><div class="gmail_quote"><br></div></div>
_______________________________________________<br>
Tagging mailing list<br>
<a href="mailto:Tagging@openstreetmap.org" target="_blank" rel="noreferrer">Tagging@openstreetmap.org</a><br>
<a href="https://lists.openstreetmap.org/listinfo/tagging" rel="noreferrer noreferrer" target="_blank">https://lists.openstreetmap.org/listinfo/tagging</a><br>
</blockquote></div>