text: // Copyright 2020 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // Test the update of tz2020a
  // https://mm.icann.org/pipermail/tz-announce/2020-April/000058.html
  //    Morocco springs forward on 2020-05-31, not 2020-05-24.
  //    Canada's Yukon advanced to -07 year-round on 2020-03-08.
  //    America/Nuuk renamed from America/Godthab.
  //    zic now supports expiration dates for leap second lists.
  
  // A. Test Morocco springs forward on 2020-05-31, not 2020-05-24.
  
  const df1 = new Intl.DateTimeFormat(
      "en",
      {timeZone: "Africa/Casablanca", timeStyle: "long", dateStyle: "long"})
  const d1 = new Date("2020-05-25T00:00:00.000Z");
  const d2 = new Date("2020-05-31T00:00:00.000Z");
  
  // Before tz2020a change will get "May 25, 2020 at 1:00:00 AM GMT+1"
  assertEquals("May 25, 2020 at 12:00:00 AM GMT", df1.format(d1));
  
  // Before tz2020a change will get "May 31, 2020 at 1:00:00 AM GMT+1"
  assertEquals("May 31, 2020 at 12:00:00 AM GMT", df1.format(d2));
  
  // B. Test Canada's Yukon advanced to -07 year-round on 2020-03-08.
  const df2 = new Intl.DateTimeFormat(
      "en",
      {timeZone: "Canada/Yukon", dateStyle: "long", timeStyle: "long"});
  const d3 = new Date("2020-03-09T00:00Z");
  const d4 = new Date("2021-03-09T00:00Z");
  
  // Before tz202a change will get "March 8, 2020 at 5:00:00 PM PDT"
  assertEquals("March 8, 2020 at 5:00:00 PM MST", df2.format(d3));
  
  // Before tz202a change will get "March 8, 2021 at 4:00:00 PM PST"
  assertEquals("March 8, 2021 at 5:00:00 PM MST", df2.format(d4));
  
  // C. Test America/Nuuk renamed from America/Godthab.
  
  // Before tz2020a will throw RangeError.
  const df3 = new Intl.DateTimeFormat("en", {timeZone: "America/Nuuk"});
  
  // Renamed timezone will return the stable name before the rename.
  assertEquals("America/Godthab", df3.resolvedOptions().timeZone);
  