1pub const MAX_NAMED_ZONE: u16 = 65535;
10
11pub const OFFSET_BASE: i32 = 1439;
14
15pub static ZONE_NAMES: [&str; 638] = [
17 "GMT",
18 "ACT",
19 "AET",
20 "AGT",
21 "ART",
22 "AST",
23 "Africa/Abidjan",
24 "Africa/Accra",
25 "Africa/Addis_Ababa",
26 "Africa/Algiers",
27 "Africa/Asmara",
28 "Africa/Asmera",
29 "Africa/Bamako",
30 "Africa/Bangui",
31 "Africa/Banjul",
32 "Africa/Bissau",
33 "Africa/Blantyre",
34 "Africa/Brazzaville",
35 "Africa/Bujumbura",
36 "Africa/Cairo",
37 "Africa/Casablanca",
38 "Africa/Ceuta",
39 "Africa/Conakry",
40 "Africa/Dakar",
41 "Africa/Dar_es_Salaam",
42 "Africa/Djibouti",
43 "Africa/Douala",
44 "Africa/El_Aaiun",
45 "Africa/Freetown",
46 "Africa/Gaborone",
47 "Africa/Harare",
48 "Africa/Johannesburg",
49 "Africa/Juba",
50 "Africa/Kampala",
51 "Africa/Khartoum",
52 "Africa/Kigali",
53 "Africa/Kinshasa",
54 "Africa/Lagos",
55 "Africa/Libreville",
56 "Africa/Lome",
57 "Africa/Luanda",
58 "Africa/Lubumbashi",
59 "Africa/Lusaka",
60 "Africa/Malabo",
61 "Africa/Maputo",
62 "Africa/Maseru",
63 "Africa/Mbabane",
64 "Africa/Mogadishu",
65 "Africa/Monrovia",
66 "Africa/Nairobi",
67 "Africa/Ndjamena",
68 "Africa/Niamey",
69 "Africa/Nouakchott",
70 "Africa/Ouagadougou",
71 "Africa/Porto-Novo",
72 "Africa/Sao_Tome",
73 "Africa/Timbuktu",
74 "Africa/Tripoli",
75 "Africa/Tunis",
76 "Africa/Windhoek",
77 "America/Adak",
78 "America/Anchorage",
79 "America/Anguilla",
80 "America/Antigua",
81 "America/Araguaina",
82 "America/Argentina/Buenos_Aires",
83 "America/Argentina/Catamarca",
84 "America/Argentina/ComodRivadavia",
85 "America/Argentina/Cordoba",
86 "America/Argentina/Jujuy",
87 "America/Argentina/La_Rioja",
88 "America/Argentina/Mendoza",
89 "America/Argentina/Rio_Gallegos",
90 "America/Argentina/Salta",
91 "America/Argentina/San_Juan",
92 "America/Argentina/San_Luis",
93 "America/Argentina/Tucuman",
94 "America/Argentina/Ushuaia",
95 "America/Aruba",
96 "America/Asuncion",
97 "America/Atikokan",
98 "America/Atka",
99 "America/Bahia",
100 "America/Bahia_Banderas",
101 "America/Barbados",
102 "America/Belem",
103 "America/Belize",
104 "America/Blanc-Sablon",
105 "America/Boa_Vista",
106 "America/Bogota",
107 "America/Boise",
108 "America/Buenos_Aires",
109 "America/Cambridge_Bay",
110 "America/Campo_Grande",
111 "America/Cancun",
112 "America/Caracas",
113 "America/Catamarca",
114 "America/Cayenne",
115 "America/Cayman",
116 "America/Chicago",
117 "America/Chihuahua",
118 "America/Coral_Harbour",
119 "America/Cordoba",
120 "America/Costa_Rica",
121 "America/Creston",
122 "America/Cuiaba",
123 "America/Curacao",
124 "America/Danmarkshavn",
125 "America/Dawson",
126 "America/Dawson_Creek",
127 "America/Denver",
128 "America/Detroit",
129 "America/Dominica",
130 "America/Edmonton",
131 "America/Eirunepe",
132 "America/El_Salvador",
133 "America/Ensenada",
134 "America/Fort_Nelson",
135 "America/Fort_Wayne",
136 "America/Fortaleza",
137 "America/Glace_Bay",
138 "America/Godthab",
139 "America/Goose_Bay",
140 "America/Grand_Turk",
141 "America/Grenada",
142 "America/Guadeloupe",
143 "America/Guatemala",
144 "America/Guayaquil",
145 "America/Guyana",
146 "America/Halifax",
147 "America/Havana",
148 "America/Hermosillo",
149 "America/Indiana/Indianapolis",
150 "America/Indiana/Knox",
151 "America/Indiana/Marengo",
152 "America/Indiana/Petersburg",
153 "America/Indiana/Tell_City",
154 "America/Indiana/Vevay",
155 "America/Indiana/Vincennes",
156 "America/Indiana/Winamac",
157 "America/Indianapolis",
158 "America/Inuvik",
159 "America/Iqaluit",
160 "America/Jamaica",
161 "America/Jujuy",
162 "America/Juneau",
163 "America/Kentucky/Louisville",
164 "America/Kentucky/Monticello",
165 "America/Knox_IN",
166 "America/Kralendijk",
167 "America/La_Paz",
168 "America/Lima",
169 "America/Los_Angeles",
170 "America/Louisville",
171 "America/Lower_Princes",
172 "America/Maceio",
173 "America/Managua",
174 "America/Manaus",
175 "America/Marigot",
176 "America/Martinique",
177 "America/Matamoros",
178 "America/Mazatlan",
179 "America/Mendoza",
180 "America/Menominee",
181 "America/Merida",
182 "America/Metlakatla",
183 "America/Mexico_City",
184 "America/Miquelon",
185 "America/Moncton",
186 "America/Monterrey",
187 "America/Montevideo",
188 "America/Montreal",
189 "America/Montserrat",
190 "America/Nassau",
191 "America/New_York",
192 "America/Nipigon",
193 "America/Nome",
194 "America/Noronha",
195 "America/North_Dakota/Beulah",
196 "America/North_Dakota/Center",
197 "America/North_Dakota/New_Salem",
198 "America/Ojinaga",
199 "America/Panama",
200 "America/Pangnirtung",
201 "America/Paramaribo",
202 "America/Phoenix",
203 "America/Port-au-Prince",
204 "America/Port_of_Spain",
205 "America/Porto_Acre",
206 "America/Porto_Velho",
207 "America/Puerto_Rico",
208 "America/Punta_Arenas",
209 "America/Rainy_River",
210 "America/Rankin_Inlet",
211 "America/Recife",
212 "America/Regina",
213 "America/Resolute",
214 "America/Rio_Branco",
215 "America/Rosario",
216 "America/Santa_Isabel",
217 "America/Santarem",
218 "America/Santiago",
219 "America/Santo_Domingo",
220 "America/Sao_Paulo",
221 "America/Scoresbysund",
222 "America/Shiprock",
223 "America/Sitka",
224 "America/St_Barthelemy",
225 "America/St_Johns",
226 "America/St_Kitts",
227 "America/St_Lucia",
228 "America/St_Thomas",
229 "America/St_Vincent",
230 "America/Swift_Current",
231 "America/Tegucigalpa",
232 "America/Thule",
233 "America/Thunder_Bay",
234 "America/Tijuana",
235 "America/Toronto",
236 "America/Tortola",
237 "America/Vancouver",
238 "America/Virgin",
239 "America/Whitehorse",
240 "America/Winnipeg",
241 "America/Yakutat",
242 "America/Yellowknife",
243 "Antarctica/Casey",
244 "Antarctica/Davis",
245 "Antarctica/DumontDUrville",
246 "Antarctica/Macquarie",
247 "Antarctica/Mawson",
248 "Antarctica/McMurdo",
249 "Antarctica/Palmer",
250 "Antarctica/Rothera",
251 "Antarctica/South_Pole",
252 "Antarctica/Syowa",
253 "Antarctica/Troll",
254 "Antarctica/Vostok",
255 "Arctic/Longyearbyen",
256 "Asia/Aden",
257 "Asia/Almaty",
258 "Asia/Amman",
259 "Asia/Anadyr",
260 "Asia/Aqtau",
261 "Asia/Aqtobe",
262 "Asia/Ashgabat",
263 "Asia/Ashkhabad",
264 "Asia/Atyrau",
265 "Asia/Baghdad",
266 "Asia/Bahrain",
267 "Asia/Baku",
268 "Asia/Bangkok",
269 "Asia/Barnaul",
270 "Asia/Beirut",
271 "Asia/Bishkek",
272 "Asia/Brunei",
273 "Asia/Calcutta",
274 "Asia/Chita",
275 "Asia/Choibalsan",
276 "Asia/Chongqing",
277 "Asia/Chungking",
278 "Asia/Colombo",
279 "Asia/Dacca",
280 "Asia/Damascus",
281 "Asia/Dhaka",
282 "Asia/Dili",
283 "Asia/Dubai",
284 "Asia/Dushanbe",
285 "Asia/Famagusta",
286 "Asia/Gaza",
287 "Asia/Harbin",
288 "Asia/Hebron",
289 "Asia/Ho_Chi_Minh",
290 "Asia/Hong_Kong",
291 "Asia/Hovd",
292 "Asia/Irkutsk",
293 "Asia/Istanbul",
294 "Asia/Jakarta",
295 "Asia/Jayapura",
296 "Asia/Jerusalem",
297 "Asia/Kabul",
298 "Asia/Kamchatka",
299 "Asia/Karachi",
300 "Asia/Kashgar",
301 "Asia/Kathmandu",
302 "Asia/Katmandu",
303 "Asia/Khandyga",
304 "Asia/Kolkata",
305 "Asia/Krasnoyarsk",
306 "Asia/Kuala_Lumpur",
307 "Asia/Kuching",
308 "Asia/Kuwait",
309 "Asia/Macao",
310 "Asia/Macau",
311 "Asia/Magadan",
312 "Asia/Makassar",
313 "Asia/Manila",
314 "Asia/Muscat",
315 "Asia/Nicosia",
316 "Asia/Novokuznetsk",
317 "Asia/Novosibirsk",
318 "Asia/Omsk",
319 "Asia/Oral",
320 "Asia/Phnom_Penh",
321 "Asia/Pontianak",
322 "Asia/Pyongyang",
323 "Asia/Qatar",
324 "Asia/Qyzylorda",
325 "Asia/Rangoon",
326 "Asia/Riyadh",
327 "Asia/Saigon",
328 "Asia/Sakhalin",
329 "Asia/Samarkand",
330 "Asia/Seoul",
331 "Asia/Shanghai",
332 "Asia/Singapore",
333 "Asia/Srednekolymsk",
334 "Asia/Taipei",
335 "Asia/Tashkent",
336 "Asia/Tbilisi",
337 "Asia/Tehran",
338 "Asia/Tel_Aviv",
339 "Asia/Thimbu",
340 "Asia/Thimphu",
341 "Asia/Tokyo",
342 "Asia/Tomsk",
343 "Asia/Ujung_Pandang",
344 "Asia/Ulaanbaatar",
345 "Asia/Ulan_Bator",
346 "Asia/Urumqi",
347 "Asia/Ust-Nera",
348 "Asia/Vientiane",
349 "Asia/Vladivostok",
350 "Asia/Yakutsk",
351 "Asia/Yangon",
352 "Asia/Yekaterinburg",
353 "Asia/Yerevan",
354 "Atlantic/Azores",
355 "Atlantic/Bermuda",
356 "Atlantic/Canary",
357 "Atlantic/Cape_Verde",
358 "Atlantic/Faeroe",
359 "Atlantic/Faroe",
360 "Atlantic/Jan_Mayen",
361 "Atlantic/Madeira",
362 "Atlantic/Reykjavik",
363 "Atlantic/South_Georgia",
364 "Atlantic/St_Helena",
365 "Atlantic/Stanley",
366 "Australia/ACT",
367 "Australia/Adelaide",
368 "Australia/Brisbane",
369 "Australia/Broken_Hill",
370 "Australia/Canberra",
371 "Australia/Currie",
372 "Australia/Darwin",
373 "Australia/Eucla",
374 "Australia/Hobart",
375 "Australia/LHI",
376 "Australia/Lindeman",
377 "Australia/Lord_Howe",
378 "Australia/Melbourne",
379 "Australia/NSW",
380 "Australia/North",
381 "Australia/Perth",
382 "Australia/Queensland",
383 "Australia/South",
384 "Australia/Sydney",
385 "Australia/Tasmania",
386 "Australia/Victoria",
387 "Australia/West",
388 "Australia/Yancowinna",
389 "BET",
390 "BST",
391 "Brazil/Acre",
392 "Brazil/DeNoronha",
393 "Brazil/East",
394 "Brazil/West",
395 "CAT",
396 "CET",
397 "CNT",
398 "CST",
399 "CST6CDT",
400 "CTT",
401 "Canada/Atlantic",
402 "Canada/Central",
403 "Canada/East-Saskatchewan",
404 "Canada/Eastern",
405 "Canada/Mountain",
406 "Canada/Newfoundland",
407 "Canada/Pacific",
408 "Canada/Saskatchewan",
409 "Canada/Yukon",
410 "Chile/Continental",
411 "Chile/EasterIsland",
412 "Cuba",
413 "EAT",
414 "ECT",
415 "EET",
416 "EST",
417 "EST5EDT",
418 "Egypt",
419 "Eire",
420 "Etc/GMT",
421 "Etc/GMT+0",
422 "Etc/GMT+1",
423 "Etc/GMT+10",
424 "Etc/GMT+11",
425 "Etc/GMT+12",
426 "Etc/GMT+2",
427 "Etc/GMT+3",
428 "Etc/GMT+4",
429 "Etc/GMT+5",
430 "Etc/GMT+6",
431 "Etc/GMT+7",
432 "Etc/GMT+8",
433 "Etc/GMT+9",
434 "Etc/GMT-0",
435 "Etc/GMT-1",
436 "Etc/GMT-10",
437 "Etc/GMT-11",
438 "Etc/GMT-12",
439 "Etc/GMT-13",
440 "Etc/GMT-14",
441 "Etc/GMT-2",
442 "Etc/GMT-3",
443 "Etc/GMT-4",
444 "Etc/GMT-5",
445 "Etc/GMT-6",
446 "Etc/GMT-7",
447 "Etc/GMT-8",
448 "Etc/GMT-9",
449 "Etc/GMT0",
450 "Etc/Greenwich",
451 "Etc/UCT",
452 "Etc/UTC",
453 "Etc/Universal",
454 "Etc/Zulu",
455 "Europe/Amsterdam",
456 "Europe/Andorra",
457 "Europe/Astrakhan",
458 "Europe/Athens",
459 "Europe/Belfast",
460 "Europe/Belgrade",
461 "Europe/Berlin",
462 "Europe/Bratislava",
463 "Europe/Brussels",
464 "Europe/Bucharest",
465 "Europe/Budapest",
466 "Europe/Busingen",
467 "Europe/Chisinau",
468 "Europe/Copenhagen",
469 "Europe/Dublin",
470 "Europe/Gibraltar",
471 "Europe/Guernsey",
472 "Europe/Helsinki",
473 "Europe/Isle_of_Man",
474 "Europe/Istanbul",
475 "Europe/Jersey",
476 "Europe/Kaliningrad",
477 "Europe/Kiev",
478 "Europe/Kirov",
479 "Europe/Lisbon",
480 "Europe/Ljubljana",
481 "Europe/London",
482 "Europe/Luxembourg",
483 "Europe/Madrid",
484 "Europe/Malta",
485 "Europe/Mariehamn",
486 "Europe/Minsk",
487 "Europe/Monaco",
488 "Europe/Moscow",
489 "Europe/Nicosia",
490 "Europe/Oslo",
491 "Europe/Paris",
492 "Europe/Podgorica",
493 "Europe/Prague",
494 "Europe/Riga",
495 "Europe/Rome",
496 "Europe/Samara",
497 "Europe/San_Marino",
498 "Europe/Sarajevo",
499 "Europe/Saratov",
500 "Europe/Simferopol",
501 "Europe/Skopje",
502 "Europe/Sofia",
503 "Europe/Stockholm",
504 "Europe/Tallinn",
505 "Europe/Tirane",
506 "Europe/Tiraspol",
507 "Europe/Ulyanovsk",
508 "Europe/Uzhgorod",
509 "Europe/Vaduz",
510 "Europe/Vatican",
511 "Europe/Vienna",
512 "Europe/Vilnius",
513 "Europe/Volgograd",
514 "Europe/Warsaw",
515 "Europe/Zagreb",
516 "Europe/Zaporozhye",
517 "Europe/Zurich",
518 "Factory",
519 "GB",
520 "GB-Eire",
521 "GMT+0",
522 "GMT-0",
523 "GMT0",
524 "Greenwich",
525 "HST",
526 "Hongkong",
527 "IET",
528 "IST",
529 "Iceland",
530 "Indian/Antananarivo",
531 "Indian/Chagos",
532 "Indian/Christmas",
533 "Indian/Cocos",
534 "Indian/Comoro",
535 "Indian/Kerguelen",
536 "Indian/Mahe",
537 "Indian/Maldives",
538 "Indian/Mauritius",
539 "Indian/Mayotte",
540 "Indian/Reunion",
541 "Iran",
542 "Israel",
543 "JST",
544 "Jamaica",
545 "Japan",
546 "Kwajalein",
547 "Libya",
548 "MET",
549 "MIT",
550 "MST",
551 "MST7MDT",
552 "Mexico/BajaNorte",
553 "Mexico/BajaSur",
554 "Mexico/General",
555 "NET",
556 "NST",
557 "NZ",
558 "NZ-CHAT",
559 "Navajo",
560 "PLT",
561 "PNT",
562 "PRC",
563 "PRT",
564 "PST",
565 "PST8PDT",
566 "Pacific/Apia",
567 "Pacific/Auckland",
568 "Pacific/Bougainville",
569 "Pacific/Chatham",
570 "Pacific/Chuuk",
571 "Pacific/Easter",
572 "Pacific/Efate",
573 "Pacific/Enderbury",
574 "Pacific/Fakaofo",
575 "Pacific/Fiji",
576 "Pacific/Funafuti",
577 "Pacific/Galapagos",
578 "Pacific/Gambier",
579 "Pacific/Guadalcanal",
580 "Pacific/Guam",
581 "Pacific/Honolulu",
582 "Pacific/Johnston",
583 "Pacific/Kiritimati",
584 "Pacific/Kosrae",
585 "Pacific/Kwajalein",
586 "Pacific/Majuro",
587 "Pacific/Marquesas",
588 "Pacific/Midway",
589 "Pacific/Nauru",
590 "Pacific/Niue",
591 "Pacific/Norfolk",
592 "Pacific/Noumea",
593 "Pacific/Pago_Pago",
594 "Pacific/Palau",
595 "Pacific/Pitcairn",
596 "Pacific/Pohnpei",
597 "Pacific/Ponape",
598 "Pacific/Port_Moresby",
599 "Pacific/Rarotonga",
600 "Pacific/Saipan",
601 "Pacific/Samoa",
602 "Pacific/Tahiti",
603 "Pacific/Tarawa",
604 "Pacific/Tongatapu",
605 "Pacific/Truk",
606 "Pacific/Wake",
607 "Pacific/Wallis",
608 "Pacific/Yap",
609 "Poland",
610 "Portugal",
611 "ROC",
612 "ROK",
613 "SST",
614 "Singapore",
615 "SystemV/AST4",
616 "SystemV/AST4ADT",
617 "SystemV/CST6",
618 "SystemV/CST6CDT",
619 "SystemV/EST5",
620 "SystemV/EST5EDT",
621 "SystemV/HST10",
622 "SystemV/MST7",
623 "SystemV/MST7MDT",
624 "SystemV/PST8",
625 "SystemV/PST8PDT",
626 "SystemV/YST9",
627 "SystemV/YST9YDT",
628 "Turkey",
629 "UCT",
630 "US/Alaska",
631 "US/Aleutian",
632 "US/Arizona",
633 "US/Central",
634 "US/East-Indiana",
635 "US/Eastern",
636 "US/Hawaii",
637 "US/Indiana-Starke",
638 "US/Michigan",
639 "US/Mountain",
640 "US/Pacific",
641 "US/Pacific-New",
642 "US/Samoa",
643 "UTC",
644 "Universal",
645 "VST",
646 "W-SU",
647 "WET",
648 "Zulu",
649 "America/Nuuk",
650 "Asia/Qostanay",
651 "Pacific/Kanton",
652 "Europe/Kyiv",
653 "America/Ciudad_Juarez",
654 "America/Coyhaique",
655];
656
657const MIN_OFFSET: i32 = -1439;
663const MAX_OFFSET: i32 = 1439;
665
666pub fn zone_name(id: u16) -> Option<&'static str> {
669 let idx = MAX_NAMED_ZONE.checked_sub(id)? as usize;
670 ZONE_NAMES.get(idx).copied()
671}
672
673pub fn offset_minutes(id: u16) -> Option<i16> {
676 let off = id as i32 - OFFSET_BASE;
677 (MIN_OFFSET..=MAX_OFFSET)
678 .contains(&off)
679 .then_some(off as i16)
680}
681
682pub fn offset_zone_id(offset_minutes: i16) -> u16 {
684 (offset_minutes as i32 + OFFSET_BASE) as u16
685}
686
687pub fn zone_label(id: u16) -> String {
690 if let Some(name) = zone_name(id) {
691 name.to_string()
692 } else if let Some(off) = offset_minutes(id) {
693 format_offset(off)
694 } else {
695 format!("zone {id}")
696 }
697}
698
699pub fn format_offset(minutes: i16) -> String {
701 let sign = if minutes < 0 { '-' } else { '+' };
702 let m = minutes.unsigned_abs() as u32;
703 format!("{sign}{:02}:{:02}", m / 60, m % 60)
704}
705
706#[cfg(test)]
707mod tests {
708 use super::*;
709
710 #[test]
711 fn named_zone_lookup() {
712 assert_eq!(zone_name(MAX_NAMED_ZONE), Some("GMT"));
713 let last = MAX_NAMED_ZONE - (ZONE_NAMES.len() as u16 - 1);
715 assert_eq!(zone_name(last), Some(ZONE_NAMES[ZONE_NAMES.len() - 1]));
716 assert_eq!(zone_name(OFFSET_BASE as u16), None);
718 }
719
720 #[test]
721 fn offset_zone_roundtrip() {
722 for off in [-1439i16, -180, -60, 0, 60, 330, 1439] {
723 let id = offset_zone_id(off);
724 assert_eq!(offset_minutes(id), Some(off));
725 }
726 assert_eq!(offset_minutes(OFFSET_BASE as u16), Some(0));
728 assert_eq!(format_offset(330), "+05:30");
729 assert_eq!(format_offset(-180), "-03:00");
730 }
731}