lib Update Request

lib.es2017.intl.d.ts

Configuration Check

My compilation target is ES2015 and my lib is es2018.

Missing / Incorrect Definition

Missing unknown in DateTimeFormatType

Sample Code

Documentation Link

In https://tc39.es/ecma402/#sec-formatdatetimepattern step 15.j, unknown is used as the fallback value. This is meant to protect against future spec change that might introduce new parts.