visualizer / vendor / phpoffice / phpexcel / Classes / PHPExcel / Shared / TimeZone.php

TimeZone.php in Visualizer – Tables & Charts Manager with Built-in AI Generator 3.0.3, at vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/TimeZone.php

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1	<?php
2
3	/**
4	* PHPExcel
5	*
6	* Copyright (c) 2006 - 2014 PHPExcel
7	*
8	* This library is free software; you can redistribute it and/or
9	* modify it under the terms of the GNU Lesser General Public
10	* License as published by the Free Software Foundation; either
11	* version 2.1 of the License, or (at your option) any later version.
12	*
13	* This library is distributed in the hope that it will be useful,
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16	* Lesser General Public License for more details.
17	*
18	* You should have received a copy of the GNU Lesser General Public
19	* License along with this library; if not, write to the Free Software
20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21	*
22	* @category PHPExcel
23	* @package PHPExcel_Shared
24	* @copyright Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
25	* @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt LGPL
26	* @version ##VERSION##, ##DATE##
27	*/
28
29
30	/**
31	* PHPExcel_Shared_TimeZone
32	*
33	* @category PHPExcel
34	* @package PHPExcel_Shared
35	* @copyright Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
36	*/
37	class PHPExcel_Shared_TimeZone
38	{
39	/*
40	* Default Timezone used for date/time conversions
41	*
42	* @private
43	* @var string
44	*/
45	protected static $_timezone = 'UTC';
46
47	/**
48	* Validate a Timezone name
49	*
50	* @param string $timezone Time zone (e.g. 'Europe/London')
51	* @return boolean Success or failure
52	*/
53	public static function _validateTimeZone($timezone) {
54	if (in_array($timezone, DateTimeZone::listIdentifiers())) {
55	return TRUE;
56	}
57	return FALSE;
58	}
59
60	/**
61	* Set the Default Timezone used for date/time conversions
62	*
63	* @param string $timezone Time zone (e.g. 'Europe/London')
64	* @return boolean Success or failure
65	*/
66	public static function setTimeZone($timezone) {
67	if (self::_validateTimezone($timezone)) {
68	self::$_timezone = $timezone;
69	return TRUE;
70	}
71	return FALSE;
72	} // function setTimezone()
73
74
75	/**
76	* Return the Default Timezone used for date/time conversions
77	*
78	* @return string Timezone (e.g. 'Europe/London')
79	*/
80	public static function getTimeZone() {
81	return self::$_timezone;
82	} // function getTimezone()
83
84
85	/**
86	* Return the Timezone transition for the specified timezone and timestamp
87	*
88	* @param DateTimeZone $objTimezone The timezone for finding the transitions
89	* @param integer $timestamp PHP date/time value for finding the current transition
90	* @return array The current transition details
91	*/
92	private static function _getTimezoneTransitions($objTimezone, $timestamp) {
93	$allTransitions = $objTimezone->getTransitions();
94	$transitions = array();
95	foreach($allTransitions as $key => $transition) {
96	if ($transition['ts'] > $timestamp) {
97	$transitions[] = ($key > 0) ? $allTransitions[$key - 1] : $transition;
98	break;
99	}
100	if (empty($transitions)) {
101	$transitions[] = end($allTransitions);
102	}
103	}
104
105	return $transitions;
106	}
107
108	/**
109	* Return the Timezone offset used for date/time conversions to/from UST
110	* This requires both the timezone and the calculated date/time to allow for local DST
111	*
112	* @param string $timezone The timezone for finding the adjustment to UST
113	* @param integer $timestamp PHP date/time value
114	* @return integer Number of seconds for timezone adjustment
115	* @throws PHPExcel_Exception
116	*/
117	public static function getTimeZoneAdjustment($timezone, $timestamp) {
118	if ($timezone !== NULL) {
119	if (!self::_validateTimezone($timezone)) {
120	throw new PHPExcel_Exception("Invalid timezone " . $timezone);
121	}
122	} else {
123	$timezone = self::$_timezone;
124	}
125
126	if ($timezone == 'UST') {
127	return 0;
128	}
129
130	$objTimezone = new DateTimeZone($timezone);
131	if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
132	$transitions = $objTimezone->getTransitions($timestamp,$timestamp);
133	} else {
134	$transitions = self::_getTimezoneTransitions($objTimezone, $timestamp);
135	}
136
137	return (count($transitions) > 0) ? $transitions[0]['offset'] : 0;
138	}
139
140	}
141