Support Time Zone IANA Ids and Windows Ids in all platforms

[tarekgh]

This change is to allow using either IANA Id or Windows Id in any platform to create a TimeZoneInfo object. That will allow users not to worry which Id type work on which platform. Also, we have the issue #49407 tracking exposing the APIs which can be used to convert IANA Ids to Windows Ids and vice versa.

As we depend on ICU library, this functionality will be limited to using the ICU. This is the default mode anyway. This functionality will not be available in the following cases:

• Running with Globalization Invariant Mode.
• Switching to use NLS on Windows.
• Using ICU library version less than 52. The only case I am aware of using version less than 52 is Centos 7 (and matching RHEL version). Upgrading ICU on such platforms will work around the issue there.

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Issue Details

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This change is to allow using either IANA Id or Windows Id in any platform to create a TimeZoneInfo object. That will allow users not to worry which Id type work on which platform. Also, we have the issue #49407 tracking exposing the APIs which can be used to convert IANA Ids to Windows Ids and vice versa.

As we depend on ICU library, this functionality will be limited to using the ICU. This is the default mode anyway. This functionality will not be available in the following cases:

• Running with Globalization Invariant Mode.
• Switching to use NLS on Windows.
• Using ICU library version less than 52. The only case I am aware of using version less than 52 is Centos 7 (and matching RHEL version).

Author:	tarekgh
Assignees:	-
Labels:	area-System.Globalization
Milestone:	-

[tarekgh]

@mattjohnsonpint I'll wait merging this till you merge yours

[tarekgh]

CC @eerhardt @lewing

[mattjohnsonpint]

This should help address #18644, and reduce the need for my TimeZoneConverter library.

[eerhardt]

This will fix #14929, correct?

[tarekgh]

This will fix #14929, correct?

That is right. thanks for linking the issue to this PR.

[tarekgh]

@steveisok @lambdageek could you please have a look if you see anything related to the mobile platforms? Thanks!

[tarekgh]

@lewing @tqiu8 looks to me that the ICU version used by the browser not having the time zone Id conversion data. I'll let you decide if this feature is important to support in the browser to enable. Let me know if I can help in anything here.

[mattjohnsonpint]

FWIW, browsers use only IANA IDs. I think the scenarios for Windows IDs are mostly server-side or desktop.

[tarekgh]

Looks the runtime-dev-innerloop CI failure is tracked by #49309

[tarekgh]

Looks the runtime (Build Browser wasm Release AllSubsets_Mono) CI failure is the issue #49499

[tarekgh]

#29683

[lewing]

@lewing @tqiu8 looks to me that the ICU version used by the browser not having the time zone Id conversion data. I'll let you decide if this feature is important to support in the browser to enable. Let me know if I can help in anything here.

It is unfortunate that the only options we have are increasing size or making browser even more unique. @tqiu8 can you take a look at the icu filters and see how much size the conversion data would add?

[lewing]

This data will impact the mobile icu sizes as well if they want to support it.

[tarekgh]

@lewing maybe @mattjohnsonpint comment #49412 (comment) make sense? and the browser should work only with IANA Ids only?

[tqiu8]

@lewing @tqiu8 looks to me that the ICU version used by the browser not having the time zone Id conversion data. I'll let you decide if this feature is important to support in the browser to enable. Let me know if I can help in anything here.

It is unfortunate that the only options we have are increasing size or making browser even more unique. @tqiu8 can you take a look at the icu filters and see how much size the conversion data would add?

Taking the idudt.json filter and enabling metaZones, takes the size of icudt.dat from 1480K to 1676K

[tarekgh]

@tqiu8 I think metaZones has a lot of other data that not needed for the name conversion functionality. Do we have the option to tailor the contents of the metaZones?

[tqiu8]

@tarekgh Yes that's definitely possible considering it's just a txt file.

[tarekgh]

@tqiu8 that is great. let's give it a try and look what size we get.

[mattjohnsonpint]

Not sure about how ICU bundles it, but strictly speaking about CLDR data, metazones aren't required for Windows ID conversion. Only windowsZones.xml and bcp47/timeZones.xml are needed.