content/browser/resources/webxr_internals/time_util.ts

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import type {Time} from 'chrome://resources/mojo/mojo/public/mojom/base/time.mojom-webui.js';

export function formatMojoTime(mojoTime: Time) {
  // The JS Date() is based off of the number of milliseconds since the
  // UNIX epoch (1970-01-01 00::00:00 UTC), while |internalValue| of the
  // base::Time (represented in mojom.Time) represents the number of
  // microseconds since the Windows FILETIME epoch (1601-01-01 00:00:00 UTC).
  // This computes the final JS time by computing the epoch delta and the
  // conversion from microseconds to milliseconds.
  const windowsEpoch = Date.UTC(1601, 0, 1, 0, 0, 0, 0);
  const unixEpoch = Date.UTC(1970, 0, 1, 0, 0, 0, 0);
  // |epochDeltaInMs| equals to base::Time::kTimeTToMicrosecondsOffset.
  const epochDeltaInMs = unixEpoch - windowsEpoch;
  const timeInMs = Number(mojoTime.internalValue) / 1000;

  return (new Date(timeInMs - epochDeltaInMs)).toLocaleString();
}

export function getCurrentDateTime() {
  const now = new Date();
  const formattedDateTime = now.toLocaleString();
  return formattedDateTime;
}