feat(time): support IANA time zones. close #14453

[konzen]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

Adds global and per-time-axis IANA time-zone support for ticks, labels, tooltips, and time utilities while preserving useUTC compatibility.

Fixed issues

• Possibility to set specific timezone for time axis #14453: Support specifying a time zone for time axes.

Details

Before: What was the problem?

Time axes could only use UTC or the browser/operating-system time zone. Charts could not select an IANA time zone or use different time zones for different axes.

After: How does it behave after the fixing?

Charts can define a global timeZone, overridden by timeZone on individual time axes. Time-axis ticks, labels, and tooltip values use the effective axis time zone.

The legacy useUTC option remains supported, and timeZone takes precedence when both are specified. Input parsing behavior is unchanged.

The implementation uses native Intl.DateTimeFormat, without external dependencies or a bundled time-zone database.

Document Info

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in docs(time): document time zone support echarts-doc#529

Misc

Security Checking

• This PR uses security-sensitive Web APIs.

ZRender Changes

• This PR depends on ZRender changes.

Related test cases or examples to use the new APIs

• test/ut/spec/scale/time.test.ts
• test/ut/spec/util/time.test.ts
• test/ut/spec/util/format.test.ts
• test/ut/spec/component/tooltip/timeZone.test.ts

Validation:

• npm test
• npm run checktype
• npm run lint
• npm run test:dts:fast

Merging options

• Please squash the commits into a single one when merging.

Other information

This PR builds on the work started in #21475, continuing it with a native Intl.DateTimeFormat implementation and completing global and per-axis time-zone support, backward compatibility, DST handling, tooltips, tests, and documentation.

[echarts-bot]

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