aboutsummaryrefslogtreecommitdiffstats
path: root/vendor/sabre/vobject/lib/Sabre/VObject/TimeZoneUtil.php
blob: c009a6af0dac945365c5029c89aa0959c58b0c7f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
<?php

namespace Sabre\VObject;

/**
 * Time zone name translation
 *
 * This file translates well-known time zone names into "Olson database" time zone names.
 *
 * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
 * @author Frank Edelhaeuser (fedel@users.sourceforge.net)
 * @author Evert Pot (http://evertpot.com/)
 * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
 */
class TimeZoneUtil {

    public static $map = array(

        // from http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/zone_tzid.html
        // snapshot taken on 2012/01/16

        // windows
        'AUS Central Standard Time'=>'Australia/Darwin',
        'AUS Eastern Standard Time'=>'Australia/Sydney',
        'Afghanistan Standard Time'=>'Asia/Kabul',
        'Alaskan Standard Time'=>'America/Anchorage',
        'Arab Standard Time'=>'Asia/Riyadh',
        'Arabian Standard Time'=>'Asia/Dubai',
        'Arabic Standard Time'=>'Asia/Baghdad',
        'Argentina Standard Time'=>'America/Buenos_Aires',
        'Armenian Standard Time'=>'Asia/Yerevan',
        'Atlantic Standard Time'=>'America/Halifax',
        'Azerbaijan Standard Time'=>'Asia/Baku',
        'Azores Standard Time'=>'Atlantic/Azores',
        'Bangladesh Standard Time'=>'Asia/Dhaka',
        'Canada Central Standard Time'=>'America/Regina',
        'Cape Verde Standard Time'=>'Atlantic/Cape_Verde',
        'Caucasus Standard Time'=>'Asia/Yerevan',
        'Cen. Australia Standard Time'=>'Australia/Adelaide',
        'Central America Standard Time'=>'America/Guatemala',
        'Central Asia Standard Time'=>'Asia/Almaty',
        'Central Brazilian Standard Time'=>'America/Cuiaba',
        'Central Europe Standard Time'=>'Europe/Budapest',
        'Central European Standard Time'=>'Europe/Warsaw',
        'Central Pacific Standard Time'=>'Pacific/Guadalcanal',
        'Central Standard Time'=>'America/Chicago',
        'Central Standard Time (Mexico)'=>'America/Mexico_City',
        'China Standard Time'=>'Asia/Shanghai',
        'Dateline Standard Time'=>'Etc/GMT+12',
        'E. Africa Standard Time'=>'Africa/Nairobi',
        'E. Australia Standard Time'=>'Australia/Brisbane',
        'E. Europe Standard Time'=>'Europe/Minsk',
        'E. South America Standard Time'=>'America/Sao_Paulo',
        'Eastern Standard Time'=>'America/New_York',
        'Egypt Standard Time'=>'Africa/Cairo',
        'Ekaterinburg Standard Time'=>'Asia/Yekaterinburg',
        'FLE Standard Time'=>'Europe/Kiev',
        'Fiji Standard Time'=>'Pacific/Fiji',
        'GMT Standard Time'=>'Europe/London',
        'GTB Standard Time'=>'Europe/Istanbul',
        'Georgian Standard Time'=>'Asia/Tbilisi',
        'Greenland Standard Time'=>'America/Godthab',
        'Greenwich Standard Time'=>'Atlantic/Reykjavik',
        'Hawaiian Standard Time'=>'Pacific/Honolulu',
        'India Standard Time'=>'Asia/Calcutta',
        'Iran Standard Time'=>'Asia/Tehran',
        'Israel Standard Time'=>'Asia/Jerusalem',
        'Jordan Standard Time'=>'Asia/Amman',
        'Kamchatka Standard Time'=>'Asia/Kamchatka',
        'Korea Standard Time'=>'Asia/Seoul',
        'Magadan Standard Time'=>'Asia/Magadan',
        'Mauritius Standard Time'=>'Indian/Mauritius',
        'Mexico Standard Time'=>'America/Mexico_City',
        'Mexico Standard Time 2'=>'America/Chihuahua',
        'Mid-Atlantic Standard Time'=>'Etc/GMT-2',
        'Middle East Standard Time'=>'Asia/Beirut',
        'Montevideo Standard Time'=>'America/Montevideo',
        'Morocco Standard Time'=>'Africa/Casablanca',
        'Mountain Standard Time'=>'America/Denver',
        'Mountain Standard Time (Mexico)'=>'America/Chihuahua',
        'Myanmar Standard Time'=>'Asia/Rangoon',
        'N. Central Asia Standard Time'=>'Asia/Novosibirsk',
        'Namibia Standard Time'=>'Africa/Windhoek',
        'Nepal Standard Time'=>'Asia/Katmandu',
        'New Zealand Standard Time'=>'Pacific/Auckland',
        'Newfoundland Standard Time'=>'America/St_Johns',
        'North Asia East Standard Time'=>'Asia/Irkutsk',
        'North Asia Standard Time'=>'Asia/Krasnoyarsk',
        'Pacific SA Standard Time'=>'America/Santiago',
        'Pacific Standard Time'=>'America/Los_Angeles',
        'Pacific Standard Time (Mexico)'=>'America/Santa_Isabel',
        'Pakistan Standard Time'=>'Asia/Karachi',
        'Paraguay Standard Time'=>'America/Asuncion',
        'Romance Standard Time'=>'Europe/Paris',
        'Russian Standard Time'=>'Europe/Moscow',
        'SA Eastern Standard Time'=>'America/Cayenne',
        'SA Pacific Standard Time'=>'America/Bogota',
        'SA Western Standard Time'=>'America/La_Paz',
        'SE Asia Standard Time'=>'Asia/Bangkok',
        'Samoa Standard Time'=>'Pacific/Apia',
        'Singapore Standard Time'=>'Asia/Singapore',
        'South Africa Standard Time'=>'Africa/Johannesburg',
        'Sri Lanka Standard Time'=>'Asia/Colombo',
        'Syria Standard Time'=>'Asia/Damascus',
        'Taipei Standard Time'=>'Asia/Taipei',
        'Tasmania Standard Time'=>'Australia/Hobart',
        'Tokyo Standard Time'=>'Asia/Tokyo',
        'Tonga Standard Time'=>'Pacific/Tongatapu',
        'US Eastern Standard Time'=>'America/Indianapolis',
        'US Mountain Standard Time'=>'America/Phoenix',
        'UTC+12'=>'Etc/GMT-12',
        'UTC-02'=>'Etc/GMT+2',
        'UTC-11'=>'Etc/GMT+11',
        'Ulaanbaatar Standard Time'=>'Asia/Ulaanbaatar',
        'Venezuela Standard Time'=>'America/Caracas',
        'Vladivostok Standard Time'=>'Asia/Vladivostok',
        'W. Australia Standard Time'=>'Australia/Perth',
        'W. Central Africa Standard Time'=>'Africa/Lagos',
        'W. Europe Standard Time'=>'Europe/Berlin',
        'West Asia Standard Time'=>'Asia/Tashkent',
        'West Pacific Standard Time'=>'Pacific/Port_Moresby',
        'Yakutsk Standard Time'=>'Asia/Yakutsk',

        // Microsoft exchange timezones
        // Source:
        // http://msdn.microsoft.com/en-us/library/ms988620%28v=exchg.65%29.aspx
        //
        // Correct timezones deduced with help from:
        // http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
        'Universal Coordinated Time' => 'UTC',
        'Casablanca, Monrovia' => 'Africa/Casablanca',
        'Greenwich Mean Time: Dublin, Edinburgh, Lisbon, London' => 'Europe/Lisbon',
        'Greenwich Mean Time; Dublin, Edinburgh, London' =>  'Europe/London',
        'Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna' => 'Europe/Berlin',
        'Belgrade, Pozsony, Budapest, Ljubljana, Prague' => 'Europe/Prague',
        'Brussels, Copenhagen, Madrid, Paris' => 'Europe/Paris',
        'Paris, Madrid, Brussels, Copenhagen' => 'Europe/Paris',
        'Prague, Central Europe' => 'Europe/Prague',
        'Sarajevo, Skopje, Sofija, Vilnius, Warsaw, Zagreb' => 'Europe/Sarajevo',
        'West Central Africa' => 'Africa/Luanda', // This was a best guess
        'Athens, Istanbul, Minsk' => 'Europe/Athens',
        'Bucharest' => 'Europe/Bucharest',
        'Cairo' => 'Africa/Cairo',
        'Harare, Pretoria' => 'Africa/Harare',
        'Helsinki, Riga, Tallinn' => 'Europe/Helsinki',
        'Israel, Jerusalem Standard Time' => 'Asia/Jerusalem',
        'Baghdad' => 'Asia/Baghdad',
        'Arab, Kuwait, Riyadh' => 'Asia/Kuwait',
        'Moscow, St. Petersburg, Volgograd' => 'Europe/Moscow',
        'East Africa, Nairobi' => 'Africa/Nairobi',
        'Tehran' => 'Asia/Tehran',
        'Abu Dhabi, Muscat' => 'Asia/Muscat', // Best guess
        'Baku, Tbilisi, Yerevan' => 'Asia/Baku',
        'Kabul' => 'Asia/Kabul',
        'Ekaterinburg' => 'Asia/Yekaterinburg',
        'Islamabad, Karachi, Tashkent' => 'Asia/Karachi',
        'Kolkata, Chennai, Mumbai, New Delhi, India Standard Time' => 'Asia/Calcutta',
        'Kathmandu, Nepal' => 'Asia/Kathmandu',
        'Almaty, Novosibirsk, North Central Asia' => 'Asia/Almaty',
        'Astana, Dhaka' => 'Asia/Dhaka',
        'Sri Jayawardenepura, Sri Lanka' => 'Asia/Colombo',
        'Rangoon' => 'Asia/Rangoon',
        'Bangkok, Hanoi, Jakarta' => 'Asia/Bangkok',
        'Krasnoyarsk' => 'Asia/Krasnoyarsk',
        'Beijing, Chongqing, Hong Kong SAR, Urumqi' => 'Asia/Shanghai',
        'Irkutsk, Ulaan Bataar' => 'Asia/Irkutsk',
        'Kuala Lumpur, Singapore' => 'Asia/Singapore',
        'Perth, Western Australia' => 'Australia/Perth',
        'Taipei' => 'Asia/Taipei',
        'Osaka, Sapporo, Tokyo' => 'Asia/Tokyo',
        'Seoul, Korea Standard time' => 'Asia/Seoul',
        'Yakutsk' => 'Asia/Yakutsk',
        'Adelaide, Central Australia' => 'Australia/Adelaide',
        'Darwin' => 'Australia/Darwin',
        'Brisbane, East Australia' => 'Australia/Brisbane',
        'Canberra, Melbourne, Sydney, Hobart (year 2000 only)' => 'Australia/Sydney',
        'Guam, Port Moresby' => 'Pacific/Guam',
        'Hobart, Tasmania' => 'Australia/Hobart',
        'Vladivostok' => 'Asia/Vladivostok',
        'Magadan, Solomon Is., New Caledonia' => 'Asia/Magadan',
        'Auckland, Wellington' => 'Pacific/Auckland',
        'Fiji Islands, Kamchatka, Marshall Is.' => 'Pacific/Fiji',
        'Nuku\'alofa, Tonga' => 'Pacific/Tongatapu',
        'Azores' => 'Atlantic/Azores',
        'Cape Verde Is.' => 'Atlantic/Cape_Verde',
        'Mid-Atlantic' => 'America/Noronha',
        'Brasilia' => 'America/Sao_Paulo', // Best guess
        'Buenos Aires' => 'America/Argentina/Buenos_Aires',
        'Greenland' => 'America/Godthab',
        'Newfoundland' => 'America/St_Johns',
        'Atlantic Time (Canada)' => 'America/Halifax',
        'Caracas, La Paz' => 'America/Caracas',
        'Santiago' => 'America/Santiago',
        'Bogota, Lima, Quito' => 'America/Bogota',
        'Eastern Time (US & Canada)' => 'America/New_York',
        'Indiana (East)' => 'America/Indiana/Indianapolis',
        'Central America' => 'America/Guatemala',
        'Central Time (US & Canada)' => 'America/Chicago',
        'Mexico City, Tegucigalpa' => 'America/Mexico_City',
        'Saskatchewan' => 'America/Edmonton',
        'Arizona' => 'America/Phoenix',
        'Mountain Time (US & Canada)' => 'America/Denver', // Best guess
        'Pacific Time (US & Canada); Tijuana' => 'America/Los_Angeles', // Best guess
        'Alaska' => 'America/Anchorage',
        'Hawaii' => 'Pacific/Honolulu',
        'Midway Island, Samoa' => 'Pacific/Midway',
        'Eniwetok, Kwajalein, Dateline Time' => 'Pacific/Kwajalein',

        // The following list are timezone names that could be generated by
        // Lotus / Domino
        'Dateline'               => 'Etc/GMT-12',
        'Samoa'                  => 'Pacific/Apia',
        'Hawaiian'               => 'Pacific/Honolulu',
        'Alaskan'                => 'America/Anchorage',
        'Pacific'                => 'America/Los_Angeles',
        'Pacific Standard Time'  => 'America/Los_Angeles',
        'Mexico Standard Time 2' => 'America/Chihuahua',
        'Mountain'               => 'America/Denver',
        'Mountain Standard Time' => 'America/Chihuahua',
        'US Mountain'            => 'America/Phoenix',
        'Canada Central'         => 'America/Edmonton',
        'Central America'        => 'America/Guatemala',
        'Central'                => 'America/Chicago',
        'Central Standard Time'  => 'America/Mexico_City',
        'Mexico'                 => 'America/Mexico_City',
        'Eastern'                => 'America/New_York',
        'SA Pacific'             => 'America/Bogota',
        'US Eastern'             => 'America/Indiana/Indianapolis',
        'Venezuela'              => 'America/Caracas',
        'Atlantic'               => 'America/Halifax',
        'Central Brazilian'      => 'America/Manaus',
        'Pacific SA'             => 'America/Santiago',
        'SA Western'             => 'America/La_Paz',
        'Newfoundland'           => 'America/St_Johns',
        'Argentina'              => 'America/Argentina/Buenos_Aires',
        'E. South America'       => 'America/Belem',
        'Greenland'              => 'America/Godthab',
        'Montevideo'             => 'America/Montevideo',
        'SA Eastern'             => 'America/Belem',
        'Mid-Atlantic'           => 'Etc/GMT-2',
        'Azores'                 => 'Atlantic/Azores',
        'Cape Verde'             => 'Atlantic/Cape_Verde',
        'Greenwich'              => 'Atlantic/Reykjavik', // No I'm serious.. Greenwich is not GMT.
        'Morocco'                => 'Africa/Casablanca',
        'Central Europe'         => 'Europe/Prague',
        'Central European'       => 'Europe/Sarajevo',
        'Romance'                => 'Europe/Paris',
        'W. Central Africa'      => 'Africa/Lagos', // Best guess
        'W. Europe'              => 'Europe/Amsterdam',
        'E. Europe'              => 'Europe/Minsk',
        'Egypt'                  => 'Africa/Cairo',
        'FLE'                    => 'Europe/Helsinki',
        'GTB'                    => 'Europe/Athens',
        'Israel'                 => 'Asia/Jerusalem',
        'Jordan'                 => 'Asia/Amman',
        'Middle East'            => 'Asia/Beirut',
        'Namibia'                => 'Africa/Windhoek',
        'South Africa'           => 'Africa/Harare',
        'Arab'                   => 'Asia/Kuwait',
        'Arabic'                 => 'Asia/Baghdad',
        'E. Africa'              => 'Africa/Nairobi',
        'Georgian'               => 'Asia/Tbilisi',
        'Russian'                => 'Europe/Moscow',
        'Iran'                   => 'Asia/Tehran',
        'Arabian'                => 'Asia/Muscat',
        'Armenian'               => 'Asia/Yerevan',
        'Azerbijan'              => 'Asia/Baku',
        'Caucasus'               => 'Asia/Yerevan',
        'Mauritius'              => 'Indian/Mauritius',
        'Afghanistan'            => 'Asia/Kabul',
        'Ekaterinburg'           => 'Asia/Yekaterinburg',
        'Pakistan'               => 'Asia/Karachi',
        'West Asia'              => 'Asia/Tashkent',
        'India'                  => 'Asia/Calcutta',
        'Sri Lanka'              => 'Asia/Colombo',
        'Nepal'                  => 'Asia/Kathmandu',
        'Central Asia'           => 'Asia/Dhaka',
        'N. Central Asia'        => 'Asia/Almaty',
        'Myanmar'                => 'Asia/Rangoon',
        'North Asia'             => 'Asia/Krasnoyarsk',
        'SE Asia'                => 'Asia/Bangkok',
        'China'                  => 'Asia/Shanghai',
        'North Asia East'        => 'Asia/Irkutsk',
        'Singapore'              => 'Asia/Singapore',
        'Taipei'                 => 'Asia/Taipei',
        'W. Australia'           => 'Australia/Perth',
        'Korea'                  => 'Asia/Seoul',
        'Tokyo'                  => 'Asia/Tokyo',
        'Yakutsk'                => 'Asia/Yakutsk',
        'AUS Central'            => 'Australia/Darwin',
        'Cen. Australia'         => 'Australia/Adelaide',
        'AUS Eastern'            => 'Australia/Sydney',
        'E. Australia'           => 'Australia/Brisbane',
        'Tasmania'               => 'Australia/Hobart',
        'Vladivostok'            => 'Asia/Vladivostok',
        'West Pacific'           => 'Pacific/Guam',
        'Central Pacific'        => 'Asia/Magadan',
        'Fiji'                   => 'Pacific/Fiji',
        'New Zealand'            => 'Pacific/Auckland',
        'Tonga'                  => 'Pacific/Tongatapu',

        // PHP 5.5.10 failed on a few timezones that were valid before. We're
        // normalizing them here.
        'CST6CDT'   => 'America/Chicago',
        'Cuba'      => 'America/Havana',
        'Egypt'     => 'Africa/Cairo',
        'Eire'      => 'Europe/Dublin',
        'EST5EDT'   => 'America/New_York',
        'Factory'   => 'UTC',
        'GB-Eire'   => 'Europe/London',
        'GMT0'      => 'UTC',
        'Greenwich' => 'UTC',
        'Hongkong'  => 'Asia/Hong_Kong',
        'Iceland'   => 'Atlantic/Reykjavik',
        'Iran'      => 'Asia/Tehran',
        'Israel'    => 'Asia/Jerusalem',
        'Jamaica'   => 'America/Jamaica',
        'Japan'     => 'Asia/Tokyo',
        'Kwajalein' => 'Pacific/Kwajalein',
        'Libya'     => 'Africa/Tripoli',
        'MST7MDT'   => 'America/Denver',
        'Navajo'    => 'America/Denver',
        'NZ-CHAT'   => 'Pacific/Chatham',
        'Poland'    => 'Europe/Warsaw',
        'Portugal'  => 'Europe/Lisbon',
        'PST8PDT'   => 'America/Los_Angeles',
        'Singapore' => 'Asia/Singapore',
        'Turkey'    => 'Europe/Istanbul',
        'Universal' => 'UTC',
        'W-SU'      => 'Europe/Moscow',
    );

    /**
     * List of microsoft exchange timezone ids.
     *
     * Source: http://msdn.microsoft.com/en-us/library/aa563018(loband).aspx
     */
    public static $microsoftExchangeMap = array(
        0  => 'UTC',
        31 => 'Africa/Casablanca',

        // Insanely, id #2 is used for both Europe/Lisbon, and Europe/Sarajevo.
        // I'm not even kidding.. We handle this special case in the
        // getTimeZone method.
        2  => 'Europe/Lisbon',
        1  => 'Europe/London',
        4  => 'Europe/Berlin',
        6  => 'Europe/Prague',
        3  => 'Europe/Paris',
        69 => 'Africa/Luanda', // This was a best guess
        7  => 'Europe/Athens',
        5  => 'Europe/Bucharest',
        49 => 'Africa/Cairo',
        50 => 'Africa/Harare',
        59 => 'Europe/Helsinki',
        27 => 'Asia/Jerusalem',
        26 => 'Asia/Baghdad',
        74 => 'Asia/Kuwait',
        51 => 'Europe/Moscow',
        56 => 'Africa/Nairobi',
        25 => 'Asia/Tehran',
        24 => 'Asia/Muscat', // Best guess
        54 => 'Asia/Baku',
        48 => 'Asia/Kabul',
        58 => 'Asia/Yekaterinburg',
        47 => 'Asia/Karachi',
        23 => 'Asia/Calcutta',
        62 => 'Asia/Kathmandu',
        46 => 'Asia/Almaty',
        71 => 'Asia/Dhaka',
        66 => 'Asia/Colombo',
        61 => 'Asia/Rangoon',
        22 => 'Asia/Bangkok',
        64 => 'Asia/Krasnoyarsk',
        45 => 'Asia/Shanghai',
        63 => 'Asia/Irkutsk',
        21 => 'Asia/Singapore',
        73 => 'Australia/Perth',
        75 => 'Asia/Taipei',
        20 => 'Asia/Tokyo',
        72 => 'Asia/Seoul',
        70 => 'Asia/Yakutsk',
        19 => 'Australia/Adelaide',
        44 => 'Australia/Darwin',
        18 => 'Australia/Brisbane',
        76 => 'Australia/Sydney',
        43 => 'Pacific/Guam',
        42 => 'Australia/Hobart',
        68 => 'Asia/Vladivostok',
        41 => 'Asia/Magadan',
        17 => 'Pacific/Auckland',
        40 => 'Pacific/Fiji',
        67 => 'Pacific/Tongatapu',
        29 => 'Atlantic/Azores',
        53 => 'Atlantic/Cape_Verde',
        30 => 'America/Noronha',
         8 => 'America/Sao_Paulo', // Best guess
        32 => 'America/Argentina/Buenos_Aires',
        60 => 'America/Godthab',
        28 => 'America/St_Johns',
         9 => 'America/Halifax',
        33 => 'America/Caracas',
        65 => 'America/Santiago',
        35 => 'America/Bogota',
        10 => 'America/New_York',
        34 => 'America/Indiana/Indianapolis',
        55 => 'America/Guatemala',
        11 => 'America/Chicago',
        37 => 'America/Mexico_City',
        36 => 'America/Edmonton',
        38 => 'America/Phoenix',
        12 => 'America/Denver', // Best guess
        13 => 'America/Los_Angeles', // Best guess
        14 => 'America/Anchorage',
        15 => 'Pacific/Honolulu',
        16 => 'Pacific/Midway',
        39 => 'Pacific/Kwajalein',
    );

    /**
     * This method will try to find out the correct timezone for an iCalendar
     * date-time value.
     *
     * You must pass the contents of the TZID parameter, as well as the full
     * calendar.
     *
     * If the lookup fails, this method will return the default PHP timezone
     * (as configured using date_default_timezone_set, or the date.timezone ini
     * setting).
     *
     * Alternatively, if $failIfUncertain is set to true, it will throw an
     * exception if we cannot accurately determine the timezone.
     *
     * @param string $tzid
     * @param Sabre\VObject\Component $vcalendar
     * @return DateTimeZone
     */
    static public function getTimeZone($tzid, Component $vcalendar = null, $failIfUncertain = false) {

        // First we will just see if the tzid is a support timezone identifier.
        //
        // The only exception is if the timezone starts with (. This is to
        // handle cases where certain microsoft products generate timezone
        // identifiers that for instance look like:
        //
        // (GMT+01.00) Sarajevo/Warsaw/Zagreb
        //
        // Since PHP 5.5.10, the first bit will be used as the timezone and
        // this method will return just GMT+01:00. This is wrong, because it
        // doesn't take DST into account.
        if ($tzid[0]!=='(') {
            try {
                return new \DateTimeZone($tzid);
            } catch (\Exception $e) {
            }
        }

        // Next, we check if the tzid is somewhere in our tzid map.
        if (isset(self::$map[$tzid])) {
            return new \DateTimeZone(self::$map[$tzid]);
        }

        // Maybe the author was hyper-lazy and just included an offset. We
        // support it, but we aren't happy about it.
        //
        // Note that the path in the source will never be taken from PHP 5.5.10
        // onwards. PHP 5.5.10 supports the "GMT+0100" style of format, so it
        // already gets returned early in this function. Once we drop support
        // for versions under PHP 5.5.10, this bit can be taken out of the
        // source.
        if (preg_match('/^GMT(\+|-)([0-9]{4})$/', $tzid, $matches)) {
            return new \DateTimeZone('Etc/GMT' . $matches[1] . ltrim(substr($matches[2],0,2),'0'));
        }

        if ($vcalendar) {

            // If that didn't work, we will scan VTIMEZONE objects
            foreach($vcalendar->select('VTIMEZONE') as $vtimezone) {

                if ((string)$vtimezone->TZID === $tzid) {

                    // Some clients add 'X-LIC-LOCATION' with the olson name.
                    if (isset($vtimezone->{'X-LIC-LOCATION'})) {

                        $lic = (string)$vtimezone->{'X-LIC-LOCATION'};

                        // Libical generators may specify strings like
                        // "SystemV/EST5EDT". For those we must remove the
                        // SystemV part.
                        if (substr($lic,0,8)==='SystemV/') {
                            $lic = substr($lic,8);
                        }

                        return self::getTimeZone($lic, null, $failIfUncertain);

                    }
                    // Microsoft may add a magic number, which we also have an
                    // answer for.
                    if (isset($vtimezone->{'X-MICROSOFT-CDO-TZID'})) {
                        $cdoId = (int)$vtimezone->{'X-MICROSOFT-CDO-TZID'}->value;

                        // 2 can mean both Europe/Lisbon and Europe/Sarajevo.
                        if ($cdoId===2 && strpos((string)$vtimezone->TZID, 'Sarajevo')!==false) {
                            return new \DateTimeZone('Europe/Sarajevo');
                        }

                        if (isset(self::$microsoftExchangeMap[$cdoId])) {
                            return new \DateTimeZone(self::$microsoftExchangeMap[$cdoId]);
                        }
                    }

                }

            }

        }

        if ($failIfUncertain) {
            throw new \InvalidArgumentException('We were unable to determine the correct PHP timezone for tzid: ' . $tzid);
        }

        // If we got all the way here, we default to UTC.
        return new \DateTimeZone(date_default_timezone_get());

    }

}