具有时差时区的时区

Question

I am checking the list of timezones using moment-timezone from moment.js

moment.tz.names()

is giving 583 item , the list is very detailed and very huge, how can I get the main timezones out of it so I create a drop down list?

it goes like this :

"Africa/Abidjan", "Africa/Accra", "Africa/Addis_Ababa", "Africa/Algiers", "Africa/Asmara", "Africa/Asmera", "Africa/Bamako", "Africa/Bangui", "Africa/Banjul", "Africa/Bissau", "Africa/Blantyre", "Africa/Brazzaville", "Africa/Bujumbura", "Africa/Cairo", "Africa/Casablanca", "Africa/Ceuta", "Africa/Conakry", "Africa/Dakar", "Africa/Dar_es_Salaam", "Africa/Djibouti", "Africa/Douala", "Africa/El_Aaiun", "Africa/Freetown", "Africa/Gaborone", "Africa/Harare", "Africa/Johannesburg", "Africa/Juba", "Africa/Kampala", "Africa/Khartoum", "Africa/Kigali", "Africa/Kinshasa", "Africa/Lagos", "Africa/Libreville", "Africa/Lome", "Africa/Luanda", "Africa/Lubumbashi", "Africa/Lusaka", "Africa/Malabo", "Africa/Maputo", "Africa/Maseru", "Africa/Mbabane", "Africa/Mogadishu", "Africa/Monrovia", "Africa/Nairobi", "Africa/Ndjamena", "Africa/Niamey", "Africa/Nouakchott", "Africa/Ouagadougou", "Africa/Porto-Novo", "Africa/Sao_Tome", "Africa/Timbuktu", "Africa/Tripoli", "Africa/Tunis", "Africa/Windhoek", "Americ a/Adak", "America/Anchorage", "America/Anguilla", "America/Antigua", "America/Araguaina", "America/Argentina/Buenos_Aires", "America/Argentina/Catamarca", "America/Argentina/ComodRivadavia", "America/Argentina/Cordoba", "America/Argentina/Jujuy", "America/Argentina/La_Rioja", "America/Argentina/Mendoza", "America/Argentina/Rio_Gallegos", "America/Argentina/Salta", "America/Argentina/San_Juan", "America/Argentina/San_Luis", "America/Argentina/Tucuman", "America/Argentina/Ushuaia", "America/Aruba", "America/Asuncion", "America/Atikokan", "America/Atka", "America/Bahia", "America/Bahia_Banderas", "America/Barbados", "America/Belem", "America/Belize", "America/Blanc-Sablon", "America/Boa_Vista", "America/Bogota", "America/Boise", "America/Buenos_Aires", ..........

thank you

Answer 1

I don't know of any such list. After all, who decides which time zones are the "main timezones"? However, one option is to do what Microsoft Windows does and sort the list by timezone offset:

From the moment docs :

moment("2016-03-03").tz("America/Toronto").format('Z'); 

will give you the offset of that particular zone, eg, -05:00 . You can get the offset for each zone, sort by offset, and then present the list. The text in the list can be the zone name, or the part after the / , with _ replaced with space (eg, America/New_York -> New York ).

Answer 2

As everyone has said, the list is the list. What I did to narrow down the list is use a session variable that has the user's timezone, and if that is null, then use a default of America/UK/South Africa/Australian timezones. For my company, this is where the majority of our customers come from. Not many Canadians, strangely enough.

This is all in PHP, and not JavaScript, but it shouldn't be too hard to read and figure out. What's important are the steps used to narrow down the results.

Here's the gist:

https://gist.github.com/NoMan2000/a262a96b159164882cd7

The output.html shows you what the default timeZone breakdown is.

The most important file is the CountryCodesAndAbbr.php file.

https://gist.github.com/NoMan2000/a262a96b159164882cd7#file-countrycodesandabbr-php

It has an array of five different country ISOs stored in JSON format. It makes a CURL request, responds with the JSON, and then stores that in a file so I don't have to keep re-downloading the files each time, and bombarding the APIs.

For our purposes, only worry about the getContinentAndCountry method, as that contains all the data we'll need. This is what moment does for you in javaScript, with some tweaks to how the API gets called.

The TimeFormatter is a class for dealing with how PHP internally handles timezones, and I need to translate between the user's country-code and the displayed timezones so I don't overwhelm them.

In PHP, I use the user's country that I get when they sign up, so I have a region to pass into the method to narrow down the results. If you don't have a session variable or some other information saved, use this API.

http://freegeoip.net

This will give you the country when you make a request to it with the user's IP. Now you have the country.

If you don't get a result back, then do what I do and default to the regions where you get the most customers, with an optional <select> field that will allow them to pick the country they want.

You have to pick whether or not you are going to use the IP or if you have some way of getting a value to the user.

Lastly, pass in the country to the TimeFormatter->getTimezonesByCountryCodeLookup(region)

https://gist.github.com/NoMan2000/a262a96b159164882cd7#file-timeformatter-php

That takes the 2 letter country code and looks it up. The end result is you end up with a much smaller result that user can navigate. I combined this with chosen.js and it enabled them to just type in their abbreviation to narrow it down.

You will have to adapt this code to your own uses, but hopefully it shows you how to go about doing it.