Intent to Implement: Add millisecondDigits option to Intl.DateTimeFormat

[Frank Tang]

Contact emails ft...@chromium.org,js...@chromium.org Explainer http://shorturl.at/adiZ4 Design docs/spec Specification: https://github.com/tc39/ecma402/pull/347 http://shorturl.at/adiZ4 TAG review No TAG review since the TC39 and ECMA402 will cover that. Summary Enhance the Intl.DateTimeFormat API by adding a “millisecondDigits” option to control the format of fractional of second. Motivation The Date object in ECMAScript store time information with precision of millisecond. Some web application developers need to format time including the detail of millisecond as fraction of second. The proposed millisecondDigits option enhances the Intl.DateTimeFormat to control how to format fractional of second which is currently not supported by the Intl.DateTimeFormat API. The value of millisecondDigits should be an integer between 0 to 3 to represent how many digits the DateTimeFormat should Risks

Interoperability and Compatibility low Firefox: No public signals Edge: No public signals Safari: No public signals Web developers: No signals Ergonomics Part of the pre-existing ICU functionality w/o need of additional data. Activation Should be easy to use by using w/ pre-existing Intl.DateTimeFormat Security low

Debuggability nothing special. Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? Yes Is this feature fully tested by web-platform-tests? Yes Tests will be added to test262 before we consider launching it. Link to entry on the Chrome Platform Status https://www.chromestatus.com/features/5704965743968256