Bug 218542

Summary: Incorrect timezone returned for Buenos Aires
Product: WebKit Reporter: Mark Wade <mwade>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: ap, mmaxfield, smoley, webkit-bug-importer, ysuzuki
Priority: P2 Keywords: InRadar
Version: Safari 14   
Hardware: All   
OS: All   
Bug Depends on:    
Bug Blocks: 218829    

Description Mark Wade 2020-11-03 16:14:21 PST
1. Set OS timezone to Buenos Aires
2. Open Javascript console and run:

Intl.DateTimeFormat().resolvedOptions().timeZone

Expected result: "America/Argentina/Buenos_Aires"
Actual result: "America/Buenos_Aires"

See https://www.iana.org/time-zones for latest timezones. America/Buenos_Aires is obsolete and not in the latest version, America/Argentina/Buenos_Aires is correct. Issue possibly applies to other timezones in Argentina.

Repeating the same steps above in Firefox gives the expected result: "America/Argentina/Buenos_Aires".
Comment 1 Alexey Proskuryakov 2020-11-03 16:49:25 PST
Presumably this will fix itself once macOS and iOS have an updated version of ICU?
Comment 2 Yusuke Suzuki 2020-11-03 20:40:49 PST
Unfortunately, as of now, I think the latest ICU does not handle it correctly.
This is a bug of ICU's TimeZone canonicalization.
V8 shows the same behavior, because V8 is doing similar thing to JSC, and both shows the wrong result because ICU does not canonicalize it correctly.
Comment 3 Radar WebKit Bug Importer 2020-11-04 10:42:20 PST
<rdar://problem/71042560>