booking-manager / assets / libs / icalendar / includes / timezone.php

timezone.php in Booking Manager – Sync WP Booking Calendar – Import Events, Export Bookings to ICS Calendar 2.0, at assets/libs/icalendar/includes/timezone.php

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1	<?php
2
3	/**
4	* Zap Calendar Time Zone Helper Class
5	*
6	* @copyright Copyright (C) 2006 - 2016 by Dan Cogliano
7	* @license GNU General Public License version 2 or later; see LICENSE.txt
8	*/
9
10	// No direct access
11	defined('_ZAPCAL') or die( 'Restricted access' );
12
13	/**
14	* Class to help create timezone section of iCalendar file
15	*
16	*/
17	class ZCTimeZoneHelper {
18
19	/**
20	* getTZNode creates VTIMEZONE section in an iCalendar file
21	*
22	* @param @startyear int start year of date range
23	*
24	* @param @endyear int end year of date range
25	*
26	* @param $tzid string PHP timezone, use underscore for multiple words (i.e. "New_York" for "New York")
27	*
28	* @param $parentnode object iCalendar object where VTIMEZONE will be created
29	*
30	* @return object return VTIMEZONE object
31	*/
32	static function getTZNode($startyear, $endyear, $tzid, $parentnode)
33	{
34	$tzmins = array();
35	$tzmaxs = array();
36	if(!array_key_exists($tzid,$tzmins) \|\| $tzmins[$tzid] > $startyear)
37	{
38	$tzmins[$tzid] = $startyear;
39	}
40	if(!array_key_exists($tzid,$tzmaxs) \|\| $tzmaxs[$tzid] < $endyear)
41	{
42	$tzmaxs[$tzid] = $endyear;
43	}
44
45	foreach(array_keys($tzmins) as $tzid)
46	{
47	$tmin = $tzmins[$tzid] - 1;
48	if(array_key_exists($tzid,$tzmaxs))
49	{
50	$tmax = $tzmaxs[$tzid] + 1;
51	}
52	else
53	{
54	$tmax = $tzmins[$tzid] + 1;
55	}
56	$tstart = gmmktime(0,0,0,1,1,$tmin);
57	$tend = gmmktime(23,59,59,12,31,$tmax);
58	$tz = new DateTimeZone($tzid);
59	$transitions = $tz->getTransitions($tstart,$tend);
60	$tzobj = new ZCiCalNode("VTIMEZONE", $parentnode, true);
61	$datanode = new ZCiCalDataNode("TZID:" . str_replace("_"," ",$tzid));
62	$tzobj->data[$datanode->getName()] = $datanode;
63	$count = 0;
64	$lasttransition = null;
65	if(count($transitions) == 1)
66	{
67	// not enough transitions found, probably UTC
68	// lets add fake transition at end for those systems that need it (i.e. Outlook)
69
70	$t2 = array();
71	$t2["isdst"] = $transitions[0]["isdst"];
72	$t2["offset"] = $transitions[0]["offset"];
73	$t2["ts"] = $tstart;
74	$t2["abbr"] = $transitions[0]["abbr"];
75	$transitions[] = $t2;
76	}
77	foreach($transitions as $transition)
78	{
79	$count++;
80	if($count == 1)
81	{
82	$lasttransition = $transition;
83	continue; // skip first item
84	}
85	if($transition["isdst"] == 1)
86	{
87	$tobj = new ZCiCalNode("DAYLIGHT", $tzobj);
88	}
89	else
90	{
91	$tobj = new ZCiCalNode("STANDARD", $tzobj);
92	}
93	//$tzobj->data[$tobj->getName()] == $tobj;
94
95	// convert timestamp to local time zone
96	$ts = ZDateHelper::toUnixDateTime(ZDateHelper::toLocalDateTime(ZDateHelper::toSQLDateTime($transition["ts"]),$tzid));
97	$datanode = new ZCiCalDataNode("DTSTART:".ZDateHelper::toICalDateTime($ts));
98	$tobj->data[$datanode->getName()] = $datanode;
99	//echo $ts . " => " . ZDateHelper::toICalDateTime($ts) . "<br/>\n"; exit;
100	$toffset = $lasttransition["offset"];
101	$thours = intval($toffset/60/60);
102	$tmins = abs($toffset)/60 - intval(abs($toffset)/60/60)*60;
103	if($thours < 0)
104	{
105	$offset = sprintf("%03d%02d",$thours,$tmins);
106	}
107	else
108	{
109	$offset = sprintf("+%02d%02d",$thours,$tmins);
110	}
111	$datanode = new ZCiCalDataNode("TZOFFSETFROM:".$offset);
112	$tobj->data[$datanode->getName()] = $datanode;
113
114	$toffset = $transition["offset"];
115	$thours = intval($toffset/60/60);
116	$tmins = abs($toffset)/60 - intval(abs($toffset)/60/60)*60;
117	if($thours < 0)
118	{
119	$offset = sprintf("%03d%02d",$thours,$tmins);
120	}
121	else
122	{
123	$offset = sprintf("+%02d%02d",$thours,$tmins);
124	}
125	$datanode = new ZCiCalDataNode("TZOFFSETTO:".$offset);
126	$tobj->data[$datanode->getName()] = $datanode;
127
128	$datanode = new ZCiCalDataNode("TZNAME:".$transition["abbr"]);
129	$tobj->data[$datanode->getName()] = $datanode;
130
131	$lasttransition = $transition;
132	}
133	}
134	return $tzobj;
135	}
136	}
137