- e2f6b8ac647271815b4fed2991f405524dd762c3 Release cctz microbenchmarks. by Alex Strelnikov <strel@google.com>

  - 924ba2a3f9fca695d73c6bf491d20669e2b96b8e Changed RawPtr to use std::addressof() instead of operato... by Abseil Team <absl-team@google.com>
  - e8cf67f9fa74d4c5632da35547025ad2301c6819 Import of CCTZ from GitHub. by Alex Strelnikov <strel@google.com>
  - 2ece8a96611afcddd7b91e0197dadb896248250c Abandon ".inc" files in favor of ".h" headers. by Jorg Brown <jorg@google.com>
  - 37f5ed5da4058f90fb3e6a2733fce5b1fd0aaedf Add exception safety tests for absl::optional<T> by Abseil Team <absl-team@google.com>
  - 337f995a866b8f905f64ca6b271b5fec8f248a60 Update WORKSPACE to grab specific commits of dependencies... by Alex Strelnikov <strel@google.com>
  - 93e5b134607a554993387ad913e6c1621606004b Release Charmap microbenchmark. by Alex Strelnikov <strel@google.com>
  - 95c2e29b6d93ec1334484ee37d91f63101c45307 Release OStringStream microbenchmarks. by Alex Strelnikov <strel@google.com>
  - 250f51839ed26dd1e6b658d35aa291413e5f4825 Internal change by Greg Falcon <gfalcon@google.com>
  - ce34900fa3d1a95a8446bc943cdd801fac95be25 Improve compatibility of cctz cc_test targets for portabl... by Shaindel Schwartz <shaindel@google.com>
  - ce7e31dbf2c1ee93c79aae5b7dc7c603cb4babcf Improve portability of cc_tests. (Mark more tests that ca... by Abseil Team <absl-team@google.com>
  - dfcd4e455923703c1a1dcd523c5f915f7990fa2a Accept strings with custom allocators as arguments to abs... by Greg Falcon <gfalcon@google.com>
  - 2946b41ed3d5b8b5a8dc11182e443cf1ab6e3bde Link against benchmark_main instead of using BENCHMARK_MA... by Alex Strelnikov <strel@google.com>
  - f09de9e03bf8edd363069c4b352d8009423f531c Adds link to doc about the formats allowed by SimpleAtof(... by Greg Miller <jgm@google.com>
  - 59b0977e7a308e0800277886cf60226b2cc426a1 Simplify the HideMask() calculation so that it doesn't us... by Jorg Brown <jorg@google.com>

GitOrigin-RevId: e2f6b8ac647271815b4fed2991f405524dd762c3
Change-Id: Ib9c8547ed7fe217fad6cb3ab1362e96181aa5cfa

4 files changed, 1017 insertions, 6 deletions

diff --git a/absl/time/BUILD.bazel b/absl/time/BUILD.bazel
index 7126f141..64cb99f7 100644
--- a/absl/time/BUILD.bazel
+++ b/absl/time/BUILD.bazel
@@ -81,10 +81,6 @@ cc_test(
     ],
     copts = ABSL_TEST_COPTS,
     tags = [
-        "no_test_android_arm",
-        "no_test_android_arm64",
-        "no_test_android_x86",
-        "no_test_ios_x86_64",
         "no_test_loonix",
     ],
     deps = [
diff --git a/absl/time/internal/cctz/BUILD.bazel b/absl/time/internal/cctz/BUILD.bazel
index 468470b4..9f1ba21c 100644
--- a/absl/time/internal/cctz/BUILD.bazel
+++ b/absl/time/internal/cctz/BUILD.bazel
@@ -81,6 +81,11 @@ cc_test(
     size = "small",
     srcs = ["src/time_zone_format_test.cc"],
     data = [":zoneinfo"],
+    tags = [
+        "no_test_android_arm",
+        "no_test_android_arm64",
+        "no_test_android_x86",
+    ],
     deps = [
         ":civil_time",
         ":time_zone",
@@ -93,6 +98,11 @@ cc_test(
     size = "small",
     srcs = ["src/time_zone_lookup_test.cc"],
     data = [":zoneinfo"],
+    tags = [
+        "no_test_android_arm",
+        "no_test_android_arm64",
+        "no_test_android_x86",
+    ],
     deps = [
         ":civil_time",
         ":time_zone",
@@ -102,6 +112,24 @@ cc_test(
 
 ### benchmarks
 
+cc_test(
+    name = "cctz_benchmark",
+    srcs = [
+        "src/cctz_benchmark.cc",
+        "src/time_zone_if.h",
+        "src/time_zone_impl.h",
+        "src/time_zone_info.h",
+        "src/tzfile.h",
+    ],
+    linkstatic = 1,
+    tags = ["benchmark"],
+    deps = [
+        ":civil_time",
+        ":time_zone",
+        "@com_github_google_benchmark//:benchmark_main",
+    ],
+)
+
 ### examples
 
 ### binaries
diff --git a/absl/time/internal/cctz/src/cctz_benchmark.cc b/absl/time/internal/cctz/src/cctz_benchmark.cc
new file mode 100644
index 00000000..f13cb4ee
--- /dev/null
+++ b/absl/time/internal/cctz/src/cctz_benchmark.cc
@@ -0,0 +1,982 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+//   Unless required by applicable law or agreed to in writing, software
+//   distributed under the License is distributed on an "AS IS" BASIS,
+//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//   See the License for the specific language governing permissions and
+//   limitations under the License.
+
+#include <algorithm>
+#include <cassert>
+#include <chrono>
+#include <ctime>
+#include <random>
+#include <string>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+#include "absl/time/internal/cctz/include/cctz/civil_time.h"
+#include "absl/time/internal/cctz/include/cctz/time_zone.h"
+#include "time_zone_impl.h"
+
+namespace {
+
+namespace cctz = absl::time_internal::cctz;
+
+void BM_Difference_Days(benchmark::State& state) {
+  const cctz::civil_day c(2014, 8, 22);
+  const cctz::civil_day epoch(1970, 1, 1);
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(c - epoch);
+  }
+}
+BENCHMARK(BM_Difference_Days);
+
+void BM_Step_Days(benchmark::State& state) {
+  const cctz::civil_day kStart(2014, 8, 22);
+  cctz::civil_day c = kStart;
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(++c);
+  }
+}
+BENCHMARK(BM_Step_Days);
+
+const char RFC3339_full[] = "%Y-%m-%dT%H:%M:%E*S%Ez";
+const char RFC3339_sec[] = "%Y-%m-%dT%H:%M:%S%Ez";
+
+const char RFC1123_full[] = "%a, %d %b %Y %H:%M:%S %z";
+const char RFC1123_no_wday[] = "%d %b %Y %H:%M:%S %z";
+
+// A list of known time-zone names.
+// TODO: Refactor with src/time_zone_lookup_test.cc.
+const char* const kTimeZoneNames[] = {
+  "Africa/Abidjan",
+  "Africa/Accra",
+  "Africa/Addis_Ababa",
+  "Africa/Algiers",
+  "Africa/Asmara",
+  "Africa/Asmera",
+  "Africa/Bamako",
+  "Africa/Bangui",
+  "Africa/Banjul",
+  "Africa/Bissau",
+  "Africa/Blantyre",
+  "Africa/Brazzaville",
+  "Africa/Bujumbura",
+  "Africa/Cairo",
+  "Africa/Casablanca",
+  "Africa/Ceuta",
+  "Africa/Conakry",
+  "Africa/Dakar",
+  "Africa/Dar_es_Salaam",
+  "Africa/Djibouti",
+  "Africa/Douala",
+  "Africa/El_Aaiun",
+  "Africa/Freetown",
+  "Africa/Gaborone",
+  "Africa/Harare",
+  "Africa/Johannesburg",
+  "Africa/Juba",
+  "Africa/Kampala",
+  "Africa/Khartoum",
+  "Africa/Kigali",
+  "Africa/Kinshasa",
+  "Africa/Lagos",
+  "Africa/Libreville",
+  "Africa/Lome",
+  "Africa/Luanda",
+  "Africa/Lubumbashi",
+  "Africa/Lusaka",
+  "Africa/Malabo",
+  "Africa/Maputo",
+  "Africa/Maseru",
+  "Africa/Mbabane",
+  "Africa/Mogadishu",
+  "Africa/Monrovia",
+  "Africa/Nairobi",
+  "Africa/Ndjamena",
+  "Africa/Niamey",
+  "Africa/Nouakchott",
+  "Africa/Ouagadougou",
+  "Africa/Porto-Novo",
+  "Africa/Sao_Tome",
+  "Africa/Timbuktu",
+  "Africa/Tripoli",
+  "Africa/Tunis",
+  "Africa/Windhoek",
+  "America/Adak",
+  "America/Anchorage",
+  "America/Anguilla",
+  "America/Antigua",
+  "America/Araguaina",
+  "America/Argentina/Buenos_Aires",
+  "America/Argentina/Catamarca",
+  "America/Argentina/ComodRivadavia",
+  "America/Argentina/Cordoba",
+  "America/Argentina/Jujuy",
+  "America/Argentina/La_Rioja",
+  "America/Argentina/Mendoza",
+  "America/Argentina/Rio_Gallegos",
+  "America/Argentina/Salta",
+  "America/Argentina/San_Juan",
+  "America/Argentina/San_Luis",
+  "America/Argentina/Tucuman",
+  "America/Argentina/Ushuaia",
+  "America/Aruba",
+  "America/Asuncion",
+  "America/Atikokan",
+  "America/Atka",
+  "America/Bahia",
+  "America/Bahia_Banderas",
+  "America/Barbados",
+  "America/Belem",
+  "America/Belize",
+  "America/Blanc-Sablon",
+  "America/Boa_Vista",
+  "America/Bogota",
+  "America/Boise",
+  "America/Buenos_Aires",
+  "America/Cambridge_Bay",
+  "America/Campo_Grande",
+  "America/Cancun",
+  "America/Caracas",
+  "America/Catamarca",
+  "America/Cayenne",
+  "America/Cayman",
+  "America/Chicago",
+  "America/Chihuahua",
+  "America/Coral_Harbour",
+  "America/Cordoba",
+  "America/Costa_Rica",
+  "America/Creston",
+  "America/Cuiaba",
+  "America/Curacao",
+  "America/Danmarkshavn",
+  "America/Dawson",
+  "America/Dawson_Creek",
+  "America/Denver",
+  "America/Detroit",
+  "America/Dominica",
+  "America/Edmonton",
+  "America/Eirunepe",
+  "America/El_Salvador",
+  "America/Ensenada",
+  "America/Fort_Nelson",
+  "America/Fort_Wayne",
+  "America/Fortaleza",
+  "America/Glace_Bay",
+  "America/Godthab",
+  "America/Goose_Bay",
+  "America/Grand_Turk",
+  "America/Grenada",
+  "America/Guadeloupe",
+  "America/Guatemala",
+  "America/Guayaquil",
+  "America/Guyana",
+  "America/Halifax",
+  "America/Havana",
+  "America/Hermosillo",
+  "America/Indiana/Indianapolis",
+  "America/Indiana/Knox",
+  "America/Indiana/Marengo",
+  "America/Indiana/Petersburg",
+  "America/Indiana/Tell_City",
+  "America/Indiana/Vevay",
+  "America/Indiana/Vincennes",
+  "America/Indiana/Winamac",
+  "America/Indianapolis",
+  "America/Inuvik",
+  "America/Iqaluit",
+  "America/Jamaica",
+  "America/Jujuy",
+  "America/Juneau",
+  "America/Kentucky/Louisville",
+  "America/Kentucky/Monticello",
+  "America/Knox_IN",
+  "America/Kralendijk",
+  "America/La_Paz",
+  "America/Lima",
+  "America/Los_Angeles",
+  "America/Louisville",
+  "America/Lower_Princes",
+  "America/Maceio",
+  "America/Managua",
+  "America/Manaus",
+  "America/Marigot",
+  "America/Martinique",
+  "America/Matamoros",
+  "America/Mazatlan",
+  "America/Mendoza",
+  "America/Menominee",
+  "America/Merida",
+  "America/Metlakatla",
+  "America/Mexico_City",
+  "America/Miquelon",
+  "America/Moncton",
+  "America/Monterrey",
+  "America/Montevideo",
+  "America/Montreal",
+  "America/Montserrat",
+  "America/Nassau",
+  "America/New_York",
+  "America/Nipigon",
+  "America/Nome",
+  "America/Noronha",
+  "America/North_Dakota/Beulah",
+  "America/North_Dakota/Center",
+  "America/North_Dakota/New_Salem",
+  "America/Ojinaga",
+  "America/Panama",
+  "America/Pangnirtung",
+  "America/Paramaribo",
+  "America/Phoenix",
+  "America/Port-au-Prince",
+  "America/Port_of_Spain",
+  "America/Porto_Acre",
+  "America/Porto_Velho",
+  "America/Puerto_Rico",
+  "America/Punta_Arenas",
+  "America/Rainy_River",
+  "America/Rankin_Inlet",
+  "America/Recife",
+  "America/Regina",
+  "America/Resolute",
+  "America/Rio_Branco",
+  "America/Rosario",
+  "America/Santa_Isabel",
+  "America/Santarem",
+  "America/Santiago",
+  "America/Santo_Domingo",
+  "America/Sao_Paulo",
+  "America/Scoresbysund",
+  "America/Shiprock",
+  "America/Sitka",
+  "America/St_Barthelemy",
+  "America/St_Johns",
+  "America/St_Kitts",
+  "America/St_Lucia",
+  "America/St_Thomas",
+  "America/St_Vincent",
+  "America/Swift_Current",
+  "America/Tegucigalpa",
+  "America/Thule",
+  "America/Thunder_Bay",
+  "America/Tijuana",
+  "America/Toronto",
+  "America/Tortola",
+  "America/Vancouver",
+  "America/Virgin",
+  "America/Whitehorse",
+  "America/Winnipeg",
+  "America/Yakutat",
+  "America/Yellowknife",
+  "Antarctica/Casey",
+  "Antarctica/Davis",
+  "Antarctica/DumontDUrville",
+  "Antarctica/Macquarie",
+  "Antarctica/Mawson",
+  "Antarctica/McMurdo",
+  "Antarctica/Palmer",
+  "Antarctica/Rothera",
+  "Antarctica/South_Pole",
+  "Antarctica/Syowa",
+  "Antarctica/Troll",
+  "Antarctica/Vostok",
+  "Arctic/Longyearbyen",
+  "Asia/Aden",
+  "Asia/Almaty",
+  "Asia/Amman",
+  "Asia/Anadyr",
+  "Asia/Aqtau",
+  "Asia/Aqtobe",
+  "Asia/Ashgabat",
+  "Asia/Ashkhabad",
+  "Asia/Atyrau",
+  "Asia/Baghdad",
+  "Asia/Bahrain",
+  "Asia/Baku",
+  "Asia/Bangkok",
+  "Asia/Barnaul",
+  "Asia/Beirut",
+  "Asia/Bishkek",
+  "Asia/Brunei",
+  "Asia/Calcutta",
+  "Asia/Chita",
+  "Asia/Choibalsan",
+  "Asia/Chongqing",
+  "Asia/Chungking",
+  "Asia/Colombo",
+  "Asia/Dacca",
+  "Asia/Damascus",
+  "Asia/Dhaka",
+  "Asia/Dili",
+  "Asia/Dubai",
+  "Asia/Dushanbe",
+  "Asia/Famagusta",
+  "Asia/Gaza",
+  "Asia/Harbin",
+  "Asia/Hebron",
+  "Asia/Ho_Chi_Minh",
+  "Asia/Hong_Kong",
+  "Asia/Hovd",
+  "Asia/Irkutsk",
+  "Asia/Istanbul",
+  "Asia/Jakarta",
+  "Asia/Jayapura",
+  "Asia/Jerusalem",
+  "Asia/Kabul",
+  "Asia/Kamchatka",
+  "Asia/Karachi",
+  "Asia/Kashgar",
+  "Asia/Kathmandu",
+  "Asia/Katmandu",
+  "Asia/Khandyga",
+  "Asia/Kolkata",
+  "Asia/Krasnoyarsk",
+  "Asia/Kuala_Lumpur",
+  "Asia/Kuching",
+  "Asia/Kuwait",
+  "Asia/Macao",
+  "Asia/Macau",
+  "Asia/Magadan",
+  "Asia/Makassar",
+  "Asia/Manila",
+  "Asia/Muscat",
+  "Asia/Nicosia",
+  "Asia/Novokuznetsk",
+  "Asia/Novosibirsk",
+  "Asia/Omsk",
+  "Asia/Oral",
+  "Asia/Phnom_Penh",
+  "Asia/Pontianak",
+  "Asia/Pyongyang",
+  "Asia/Qatar",
+  "Asia/Qyzylorda",
+  "Asia/Rangoon",
+  "Asia/Riyadh",
+  "Asia/Saigon",
+  "Asia/Sakhalin",
+  "Asia/Samarkand",
+  "Asia/Seoul",
+  "Asia/Shanghai",
+  "Asia/Singapore",
+  "Asia/Srednekolymsk",
+  "Asia/Taipei",
+  "Asia/Tashkent",
+  "Asia/Tbilisi",
+  "Asia/Tehran",
+  "Asia/Tel_Aviv",
+  "Asia/Thimbu",
+  "Asia/Thimphu",
+  "Asia/Tokyo",
+  "Asia/Tomsk",
+  "Asia/Ujung_Pandang",
+  "Asia/Ulaanbaatar",
+  "Asia/Ulan_Bator",
+  "Asia/Urumqi",
+  "Asia/Ust-Nera",
+  "Asia/Vientiane",
+  "Asia/Vladivostok",
+  "Asia/Yakutsk",
+  "Asia/Yangon",
+  "Asia/Yekaterinburg",
+  "Asia/Yerevan",
+  "Atlantic/Azores",
+  "Atlantic/Bermuda",
+  "Atlantic/Canary",
+  "Atlantic/Cape_Verde",
+  "Atlantic/Faeroe",
+  "Atlantic/Faroe",
+  "Atlantic/Jan_Mayen",
+  "Atlantic/Madeira",
+  "Atlantic/Reykjavik",
+  "Atlantic/South_Georgia",
+  "Atlantic/St_Helena",
+  "Atlantic/Stanley",
+  "Australia/ACT",
+  "Australia/Adelaide",
+  "Australia/Brisbane",
+  "Australia/Broken_Hill",
+  "Australia/Canberra",
+  "Australia/Currie",
+  "Australia/Darwin",
+  "Australia/Eucla",
+  "Australia/Hobart",
+  "Australia/LHI",
+  "Australia/Lindeman",
+  "Australia/Lord_Howe",
+  "Australia/Melbourne",
+  "Australia/NSW",
+  "Australia/North",
+  "Australia/Perth",
+  "Australia/Queensland",
+  "Australia/South",
+  "Australia/Sydney",
+  "Australia/Tasmania",
+  "Australia/Victoria",
+  "Australia/West",
+  "Australia/Yancowinna",
+  "Brazil/Acre",
+  "Brazil/DeNoronha",
+  "Brazil/East",
+  "Brazil/West",
+  "CET",
+  "CST6CDT",
+  "Canada/Atlantic",
+  "Canada/Central",
+  "Canada/Eastern",
+  "Canada/Mountain",
+  "Canada/Newfoundland",
+  "Canada/Pacific",
+  "Canada/Saskatchewan",
+  "Canada/Yukon",
+  "Chile/Continental",
+  "Chile/EasterIsland",
+  "Cuba",
+  "EET",
+  "EST",
+  "EST5EDT",
+  "Egypt",
+  "Eire",
+  "Etc/GMT",
+  "Etc/GMT+0",
+  "Etc/GMT+1",
+  "Etc/GMT+10",
+  "Etc/GMT+11",
+  "Etc/GMT+12",
+  "Etc/GMT+2",
+  "Etc/GMT+3",
+  "Etc/GMT+4",
+  "Etc/GMT+5",
+  "Etc/GMT+6",
+  "Etc/GMT+7",
+  "Etc/GMT+8",
+  "Etc/GMT+9",
+  "Etc/GMT-0",
+  "Etc/GMT-1",
+  "Etc/GMT-10",
+  "Etc/GMT-11",
+  "Etc/GMT-12",
+  "Etc/GMT-13",
+  "Etc/GMT-14",
+  "Etc/GMT-2",
+  "Etc/GMT-3",
+  "Etc/GMT-4",
+  "Etc/GMT-5",
+  "Etc/GMT-6",
+  "Etc/GMT-7",
+  "Etc/GMT-8",
+  "Etc/GMT-9",
+  "Etc/GMT0",
+  "Etc/Greenwich",
+  "Etc/UCT",
+  "Etc/UTC",
+  "Etc/Universal",
+  "Etc/Zulu",
+  "Europe/Amsterdam",
+  "Europe/Andorra",
+  "Europe/Astrakhan",
+  "Europe/Athens",
+  "Europe/Belfast",
+  "Europe/Belgrade",
+  "Europe/Berlin",
+  "Europe/Bratislava",
+  "Europe/Brussels",
+  "Europe/Bucharest",
+  "Europe/Budapest",
+  "Europe/Busingen",
+  "Europe/Chisinau",
+  "Europe/Copenhagen",
+  "Europe/Dublin",
+  "Europe/Gibraltar",
+  "Europe/Guernsey",
+  "Europe/Helsinki",
+  "Europe/Isle_of_Man",
+  "Europe/Istanbul",
+  "Europe/Jersey",
+  "Europe/Kaliningrad",
+  "Europe/Kiev",
+  "Europe/Kirov",
+  "Europe/Lisbon",
+  "Europe/Ljubljana",
+  "Europe/London",
+  "Europe/Luxembourg",
+  "Europe/Madrid",
+  "Europe/Malta",
+  "Europe/Mariehamn",
+  "Europe/Minsk",
+  "Europe/Monaco",
+  "Europe/Moscow",
+  "Europe/Nicosia",
+  "Europe/Oslo",
+  "Europe/Paris",
+  "Europe/Podgorica",
+  "Europe/Prague",
+  "Europe/Riga",
+  "Europe/Rome",
+  "Europe/Samara",
+  "Europe/San_Marino",
+  "Europe/Sarajevo",
+  "Europe/Saratov",
+  "Europe/Simferopol",
+  "Europe/Skopje",
+  "Europe/Sofia",
+  "Europe/Stockholm",
+  "Europe/Tallinn",
+  "Europe/Tirane",
+  "Europe/Tiraspol",
+  "Europe/Ulyanovsk",
+  "Europe/Uzhgorod",
+  "Europe/Vaduz",
+  "Europe/Vatican",
+  "Europe/Vienna",
+  "Europe/Vilnius",
+  "Europe/Volgograd",
+  "Europe/Warsaw",
+  "Europe/Zagreb",
+  "Europe/Zaporozhye",
+  "Europe/Zurich",
+  "GB",
+  "GB-Eire",
+  "GMT",
+  "GMT+0",
+  "GMT-0",
+  "GMT0",
+  "Greenwich",
+  "HST",
+  "Hongkong",
+  "Iceland",
+  "Indian/Antananarivo",
+  "Indian/Chagos",
+  "Indian/Christmas",
+  "Indian/Cocos",
+  "Indian/Comoro",
+  "Indian/Kerguelen",
+  "Indian/Mahe",
+  "Indian/Maldives",
+  "Indian/Mauritius",
+  "Indian/Mayotte",
+  "Indian/Reunion",
+  "Iran",
+  "Israel",
+  "Jamaica",
+  "Japan",
+  "Kwajalein",
+  "Libya",
+  "MET",
+  "MST",
+  "MST7MDT",
+  "Mexico/BajaNorte",
+  "Mexico/BajaSur",
+  "Mexico/General",
+  "NZ",
+  "NZ-CHAT",
+  "Navajo",
+  "PRC",
+  "PST8PDT",
+  "Pacific/Apia",
+  "Pacific/Auckland",
+  "Pacific/Bougainville",
+  "Pacific/Chatham",
+  "Pacific/Chuuk",
+  "Pacific/Easter",
+  "Pacific/Efate",
+  "Pacific/Enderbury",
+  "Pacific/Fakaofo",
+  "Pacific/Fiji",
+  "Pacific/Funafuti",
+  "Pacific/Galapagos",
+  "Pacific/Gambier",
+  "Pacific/Guadalcanal",
+  "Pacific/Guam",
+  "Pacific/Honolulu",
+  "Pacific/Johnston",
+  "Pacific/Kiritimati",
+  "Pacific/Kosrae",
+  "Pacific/Kwajalein",
+  "Pacific/Majuro",
+  "Pacific/Marquesas",
+  "Pacific/Midway",
+  "Pacific/Nauru",
+  "Pacific/Niue",
+  "Pacific/Norfolk",
+  "Pacific/Noumea",
+  "Pacific/Pago_Pago",
+  "Pacific/Palau",
+  "Pacific/Pitcairn",
+  "Pacific/Pohnpei",
+  "Pacific/Ponape",
+  "Pacific/Port_Moresby",
+  "Pacific/Rarotonga",
+  "Pacific/Saipan",
+  "Pacific/Samoa",
+  "Pacific/Tahiti",
+  "Pacific/Tarawa",
+  "Pacific/Tongatapu",
+  "Pacific/Truk",
+  "Pacific/Wake",
+  "Pacific/Wallis",
+  "Pacific/Yap",
+  "Poland",
+  "Portugal",
+  "ROC",
+  "ROK",
+  "Singapore",
+  "Turkey",
+  "UCT",
+  "US/Alaska",
+  "US/Aleutian",
+  "US/Arizona",
+  "US/Central",
+  "US/East-Indiana",
+  "US/Eastern",
+  "US/Hawaii",
+  "US/Indiana-Starke",
+  "US/Michigan",
+  "US/Mountain",
+  "US/Pacific",
+  "US/Samoa",
+  "UTC",
+  "Universal",
+  "W-SU",
+  "WET",
+  "Zulu",
+  nullptr
+};
+
+std::vector<std::string> AllTimeZoneNames() {
+  std::vector<std::string> names;
+  for (const char* const* namep = kTimeZoneNames; *namep != nullptr; ++namep) {
+    names.push_back(std::string("file:") + *namep);
+  }
+  assert(!names.empty());
+
+  std::mt19937 urbg(42);  // a UniformRandomBitGenerator with fixed seed
+  std::shuffle(names.begin(), names.end(), urbg);
+  return names;
+}
+
+cctz::time_zone TestTimeZone() {
+  cctz::time_zone tz;
+  cctz::load_time_zone("America/Los_Angeles", &tz);
+  return tz;
+}
+
+void BM_Zone_LoadUTCTimeZoneFirst(benchmark::State& state) {
+  cctz::time_zone tz;
+  cctz::load_time_zone("UTC", &tz);  // in case we're first
+  cctz::time_zone::Impl::ClearTimeZoneMapTestOnly();
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::load_time_zone("UTC", &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadUTCTimeZoneFirst);
+
+void BM_Zone_LoadUTCTimeZoneLast(benchmark::State& state) {
+  cctz::time_zone tz;
+  for (const auto& name : AllTimeZoneNames()) {
+    cctz::load_time_zone(name, &tz);  // prime cache
+  }
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::load_time_zone("UTC", &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadUTCTimeZoneLast);
+
+void BM_Zone_LoadTimeZoneFirst(benchmark::State& state) {
+  cctz::time_zone tz = cctz::utc_time_zone();  // in case we're first
+  const std::string name = "file:America/Los_Angeles";
+  while (state.KeepRunning()) {
+    state.PauseTiming();
+    cctz::time_zone::Impl::ClearTimeZoneMapTestOnly();
+    state.ResumeTiming();
+    benchmark::DoNotOptimize(cctz::load_time_zone(name, &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadTimeZoneFirst);
+
+void BM_Zone_LoadTimeZoneCached(benchmark::State& state) {
+  cctz::time_zone tz = cctz::utc_time_zone();  // in case we're first
+  cctz::time_zone::Impl::ClearTimeZoneMapTestOnly();
+  const std::string name = "file:America/Los_Angeles";
+  cctz::load_time_zone(name, &tz);  // prime cache
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::load_time_zone(name, &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadTimeZoneCached);
+
+void BM_Zone_LoadLocalTimeZoneCached(benchmark::State& state) {
+  cctz::utc_time_zone();  // in case we're first
+  cctz::time_zone::Impl::ClearTimeZoneMapTestOnly();
+  cctz::local_time_zone();  // prime cache
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::local_time_zone());
+  }
+}
+BENCHMARK(BM_Zone_LoadLocalTimeZoneCached);
+
+void BM_Zone_LoadAllTimeZonesFirst(benchmark::State& state) {
+  cctz::time_zone tz;
+  const std::vector<std::string> names = AllTimeZoneNames();
+  for (auto index = names.size(); state.KeepRunning(); ++index) {
+    if (index == names.size()) {
+      index = 0;
+    }
+    if (index == 0) {
+      state.PauseTiming();
+      cctz::time_zone::Impl::ClearTimeZoneMapTestOnly();
+      state.ResumeTiming();
+    }
+    benchmark::DoNotOptimize(cctz::load_time_zone(names[index], &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadAllTimeZonesFirst);
+
+void BM_Zone_LoadAllTimeZonesCached(benchmark::State& state) {
+  cctz::time_zone tz;
+  const std::vector<std::string> names = AllTimeZoneNames();
+  for (const auto& name : names) {
+    cctz::load_time_zone(name, &tz);  // prime cache
+  }
+  for (auto index = names.size(); state.KeepRunning(); ++index) {
+    if (index == names.size()) {
+      index = 0;
+    }
+    benchmark::DoNotOptimize(cctz::load_time_zone(names[index], &tz));
+  }
+}
+BENCHMARK(BM_Zone_LoadAllTimeZonesCached);
+
+void BM_Zone_TimeZoneImplGetImplicit(benchmark::State& state) {
+  cctz::time_zone tz;  // implicit UTC
+  cctz::time_zone::Impl::get(tz);
+  while (state.KeepRunning()) {
+    cctz::time_zone::Impl::get(tz);
+  }
+}
+BENCHMARK(BM_Zone_TimeZoneImplGetImplicit);
+
+void BM_Zone_TimeZoneImplGetExplicit(benchmark::State& state) {
+  cctz::time_zone tz = cctz::utc_time_zone();  // explicit UTC
+  cctz::time_zone::Impl::get(tz);
+  while (state.KeepRunning()) {
+    cctz::time_zone::Impl::get(tz);
+  }
+}
+BENCHMARK(BM_Zone_TimeZoneImplGetExplicit);
+
+void BM_Zone_UTCTimeZone(benchmark::State& state) {
+  cctz::time_zone tz;
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::utc_time_zone());
+  }
+}
+BENCHMARK(BM_Zone_UTCTimeZone);
+
+// In each "ToDateTime" benchmark we switch between two instants
+// separated by at least one transition in order to defeat any
+// internal caching of previous results (e.g., see local_time_hint_).
+//
+// The "UTC" variants use UTC instead of the Google/local time zone.
+
+void BM_Time_ToDateTime_CCTZ(benchmark::State& state) {
+  const cctz::time_zone tz = TestTimeZone();
+  std::chrono::system_clock::time_point tp =
+      std::chrono::system_clock::from_time_t(1384569027);
+  std::chrono::system_clock::time_point tp2 =
+      std::chrono::system_clock::from_time_t(1418962578);
+  while (state.KeepRunning()) {
+    std::swap(tp, tp2);
+    tp += std::chrono::seconds(1);
+    benchmark::DoNotOptimize(cctz::convert(tp, tz));
+  }
+}
+BENCHMARK(BM_Time_ToDateTime_CCTZ);
+
+void BM_Time_ToDateTime_Libc(benchmark::State& state) {
+  // No timezone support, so just use localtime.
+  time_t t = 1384569027;
+  time_t t2 = 1418962578;
+  struct tm tm;
+  while (state.KeepRunning()) {
+    std::swap(t, t2);
+    t += 1;
+#if defined(_WIN32) || defined(_WIN64)
+    benchmark::DoNotOptimize(localtime_s(&tm, &t));
+#else
+    benchmark::DoNotOptimize(localtime_r(&t, &tm));
+#endif
+  }
+}
+BENCHMARK(BM_Time_ToDateTime_Libc);
+
+void BM_Time_ToDateTimeUTC_CCTZ(benchmark::State& state) {
+  const cctz::time_zone tz = cctz::utc_time_zone();
+  std::chrono::system_clock::time_point tp =
+      std::chrono::system_clock::from_time_t(1384569027);
+  while (state.KeepRunning()) {
+    tp += std::chrono::seconds(1);
+    benchmark::DoNotOptimize(cctz::convert(tp, tz));
+  }
+}
+BENCHMARK(BM_Time_ToDateTimeUTC_CCTZ);
+
+void BM_Time_ToDateTimeUTC_Libc(benchmark::State& state) {
+  time_t t = 1384569027;
+  struct tm tm;
+  while (state.KeepRunning()) {
+    t += 1;
+#if defined(_WIN32) || defined(_WIN64)
+    benchmark::DoNotOptimize(gmtime_s(&tm, &t));
+#else
+    benchmark::DoNotOptimize(gmtime_r(&t, &tm));
+#endif
+  }
+}
+BENCHMARK(BM_Time_ToDateTimeUTC_Libc);
+
+// In each "FromDateTime" benchmark we switch between two YMDhms
+// values separated by at least one transition in order to defeat any
+// internal caching of previous results (e.g., see time_local_hint_).
+//
+// The "UTC" variants use UTC instead of the Google/local time zone.
+// The "Day0" variants require normalization of the day of month.
+
+void BM_Time_FromDateTime_CCTZ(benchmark::State& state) {
+  const cctz::time_zone tz = TestTimeZone();
+  int i = 0;
+  while (state.KeepRunning()) {
+    if ((i++ & 1) == 0) {
+      benchmark::DoNotOptimize(
+          cctz::convert(cctz::civil_second(2014, 12, 18, 20, 16, 18), tz));
+    } else {
+      benchmark::DoNotOptimize(
+          cctz::convert(cctz::civil_second(2013, 11, 15, 18, 30, 27), tz));
+    }
+  }
+}
+BENCHMARK(BM_Time_FromDateTime_CCTZ);
+
+void BM_Time_FromDateTime_Libc(benchmark::State& state) {
+  // No timezone support, so just use localtime.
+  int i = 0;
+  while (state.KeepRunning()) {
+    struct tm tm;
+    if ((i++ & 1) == 0) {
+      tm.tm_year = 2014 - 1900;
+      tm.tm_mon = 12 - 1;
+      tm.tm_mday = 18;
+      tm.tm_hour = 20;
+      tm.tm_min = 16;
+      tm.tm_sec = 18;
+    } else {
+      tm.tm_year = 2013 - 1900;
+      tm.tm_mon = 11 - 1;
+      tm.tm_mday = 15;
+      tm.tm_hour = 18;
+      tm.tm_min = 30;
+      tm.tm_sec = 27;
+    }
+    tm.tm_isdst = -1;
+    benchmark::DoNotOptimize(mktime(&tm));
+  }
+}
+BENCHMARK(BM_Time_FromDateTime_Libc);
+
+void BM_Time_FromDateTimeUTC_CCTZ(benchmark::State& state) {
+  const cctz::time_zone tz = cctz::utc_time_zone();
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(
+        cctz::convert(cctz::civil_second(2014, 12, 18, 20, 16, 18), tz));
+  }
+}
+BENCHMARK(BM_Time_FromDateTimeUTC_CCTZ);
+
+// There is no BM_Time_FromDateTimeUTC_Libc.
+
+void BM_Time_FromDateTimeDay0_CCTZ(benchmark::State& state) {
+  const cctz::time_zone tz = TestTimeZone();
+  int i = 0;
+  while (state.KeepRunning()) {
+    if ((i++ & 1) == 0) {
+      benchmark::DoNotOptimize(
+          cctz::convert(cctz::civil_second(2014, 12, 0, 20, 16, 18), tz));
+    } else {
+      benchmark::DoNotOptimize(
+          cctz::convert(cctz::civil_second(2013, 11, 0, 18, 30, 27), tz));
+    }
+  }
+}
+BENCHMARK(BM_Time_FromDateTimeDay0_CCTZ);
+
+void BM_Time_FromDateTimeDay0_Libc(benchmark::State& state) {
+  // No timezone support, so just use localtime.
+  int i = 0;
+  while (state.KeepRunning()) {
+    struct tm tm;
+    if ((i++ & 1) == 0) {
+      tm.tm_year = 2014 - 1900;
+      tm.tm_mon = 12 - 1;
+      tm.tm_mday = 0;
+      tm.tm_hour = 20;
+      tm.tm_min = 16;
+      tm.tm_sec = 18;
+    } else {
+      tm.tm_year = 2013 - 1900;
+      tm.tm_mon = 11 - 1;
+      tm.tm_mday = 0;
+      tm.tm_hour = 18;
+      tm.tm_min = 30;
+      tm.tm_sec = 27;
+    }
+    tm.tm_isdst = -1;
+    benchmark::DoNotOptimize(mktime(&tm));
+  }
+}
+BENCHMARK(BM_Time_FromDateTimeDay0_Libc);
+
+const char* const kFormats[] = {
+    RFC1123_full,         // 0
+    RFC1123_no_wday,      // 1
+    RFC3339_full,         // 2
+    RFC3339_sec,          // 3
+    "%Y-%m-%dT%H:%M:%S",  // 4
+    "%Y-%m-%d",           // 5
+};
+const int kNumFormats = sizeof(kFormats) / sizeof(kFormats[0]);
+
+void BM_Format_FormatTime(benchmark::State& state) {
+  const std::string fmt = kFormats[state.range(0)];
+  state.SetLabel(fmt);
+  const cctz::time_zone tz = TestTimeZone();
+  const std::chrono::system_clock::time_point tp =
+      cctz::convert(cctz::civil_second(1977, 6, 28, 9, 8, 7), tz) +
+      std::chrono::microseconds(1);
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::format(fmt, tp, tz));
+  }
+}
+BENCHMARK(BM_Format_FormatTime)->DenseRange(0, kNumFormats - 1);
+
+void BM_Format_ParseTime(benchmark::State& state) {
+  const std::string fmt = kFormats[state.range(0)];
+  state.SetLabel(fmt);
+  const cctz::time_zone tz = TestTimeZone();
+  std::chrono::system_clock::time_point tp =
+      cctz::convert(cctz::civil_second(1977, 6, 28, 9, 8, 7), tz) +
+      std::chrono::microseconds(1);
+  const std::string when = cctz::format(fmt, tp, tz);
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(cctz::parse(fmt, when, tz, &tp));
+  }
+}
+BENCHMARK(BM_Format_ParseTime)->DenseRange(0, kNumFormats - 1);
+
+}  // namespace
diff --git a/absl/time/internal/cctz/src/time_zone_format_test.cc b/absl/time/internal/cctz/src/time_zone_format_test.cc
index 6cea0360..3a5f19ac 100644
--- a/absl/time/internal/cctz/src/time_zone_format_test.cc
+++ b/absl/time/internal/cctz/src/time_zone_format_test.cc
@@ -463,8 +463,13 @@ TEST(Format, ExtendedSecondOffset) {
 
   EXPECT_TRUE(load_time_zone("Europe/Moscow", &tz));
   tp = convert(civil_second(1919, 6, 30, 23, 59, 59), utc);
-  TestFormatSpecifier(tp, tz, "%E*z", "+04:31:19");
-  TestFormatSpecifier(tp, tz, "%Ez", "+04:31");
+  if (tz.lookup(tp).offset == 4 * 60 * 60) {
+    // We're likely dealing with zoneinfo that doesn't support really old
+    // timestamps, so Europe/Moscow never looks to be on local mean time.
+  } else {
+    TestFormatSpecifier(tp, tz, "%E*z", "+04:31:19");
+    TestFormatSpecifier(tp, tz, "%Ez", "+04:31");
+  }
   tp += seconds(1);
   TestFormatSpecifier(tp, tz, "%E*z", "+04:00:00");
 }