ICS文件动态时区问题

Question

我试图在PHP中动态生成ics文件，其中时区根据给定的位置是动态的。一切都很好，但有一个夏令时问题，即它显示一个小时左右的时差。现在为了解决这个问题，我必须动态地使用DAYLIGHT。但是我不知道如何动态地使用它，或者从哪里可以得到与给定时区相关的TZOFFSETFROM和TZOFFSETTO偏移量。

例如:

    $timeZone = "America/Denver" // dynamically fetched from DB
      $ical = "BEGIN:VCALENDARn";
      $ical .= "VERSION:2.0n";
      $ical .= "PRODID:-//LokalMotion//LokalMotion Events v1.0//ENn";
      $ical .= "CALSCALE:GREGORIANn";
      $ical .= "METHOD:PUBLISHn";
      $ical .= "X-WR-CALNAME:LokalMotion Eventsn";
      $ical .= "X-MS-OLK-FORCEINSPECTOROPEN:TRUEn";
      $ical .= "BEGIN:VTIMEZONEn";
      $ical .= "TZID:{$timeZone}n";
      $ical .= "TZURL:http://tzurl.org/zoneinfo-outlook/{$timeZone}n";
      $ical .= "X-LIC-LOCATION:{$timeZone}n";
      $ical .= "END:VTIMEZONEn";
      $ical .= "BEGIN:VEVENTn";
      $ical .= "DTSTAMP:".date('YmdTHisZ')."n";
      $ical .= "DTSTART;TZID={$timeZone}:{$start_date}n";
      $ical .= "DTEND;TZID={$timeZone}:{$end_date}n";
      $ical .= "STATUS:CONFIRMEDn";
      $ical .= "SUMMARY:{$title}n";
      $ical .= "DESCRIPTION:{$description}n";
      $ical .= "ORGANIZER;CN=Reminder:MAILTO:[e-mail]";
      $ical .= "CLASS:PUBLICn";
      $ical .= "CREATED:{$start_date}Zn";
      $ical .= "LOCATION:{$location}n";
      $ical .= "URL:http://www.mysite.comn";
      $ical .= "SEQUENCE:1n";
      $ical .= "LAST-MODIFIED:".date('YmdTHisZ')."n";
      $ical .= "UID:{$title}[e-mail]";
      $ical .= "END:VEVENTn";
      $ical .= "END:VCALENDAR";    
echo $ical;

现在如何根据位置动态使用日光，比如位置可以是'America/Caracas' ..等

$ical .= "BEGIN:DAYLIGHT";
$ical .= "TZOFFSETFROM:{}"; //I need this dynamic
$ical .= "TZOFFSETTO:{}";//I need this dynamic
$ical .= "TZNAME:EDT";
$ical .= "DTSTART;TZID={$timeZone}:{$start_date}n";
$ical .= "RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU";
$ical .= "END:DAYLIGHT";

Answer 1

在转换时间和日期之前，您应该在PHP中设置正确的时区，以便引擎知道您正在使用的时区的时间特征:

date_default_timezone_set('America/Mexico_City');
$start_date = date('c', time());   // ISO date 8601 of "right now"
$start_zone = date('O', time());   // TZOFFSETFROM format  of "right now"
date_default_timezone_set('America/Denver');
$to_zone = date('O', time());   // TZOFFSETTO of "right now"

希望能有所帮助