TypeScript: `ZonedDateTime.from()` doesn't require `timeZone` property, but runtime throws error

[mohhh-ok]

Current Behavior

When calling Temporal.ZonedDateTime.from() with an object that's missing the required timeZone property, TypeScript does not report a type error. However, at runtime, the code throws:

Uncaught TypeError: required property 'timeZone' missing or undefined

Example Code

import { Temporal } from "@js-temporal/polyfill";

// TypeScript does NOT error on this, but it should
const zdt = Temporal.ZonedDateTime.from({
  year: 2026,
  month: 1,
  day: 1
  // missing timeZone!
});

Expected Behavior

TypeScript should report a type error indicating that timeZone is required.

Root Cause

In index.d.ts, the ZonedDateTimeLike type defines timeZone as optional:

export type ZonedDateTimeLike = {
  // ... other properties
  timeZone?: TimeZoneLike;  // ← should NOT be optional
  // ... other properties
};

Suggested Fix

The timeZone property should be required in ZonedDateTimeLike:

export type ZonedDateTimeLike = {
  // ... other properties
  timeZone: TimeZoneLike;  // ← remove the `?`
  // ... other properties
};

Environment

• @js-temporal/polyfill version: 0.5.1
• TypeScript version: 5.9.3