晚年，但在这里它是如何工作的我，也许这将帮助别人谁在这个问题发生。
我从来没有尝试TZOFFSETFROM ...所以不知道这是关于什么，或者即使它应该工作。但是，如果将时区放入DTSTART和DTEND中，它将自动调整。您只需要日期为UTC，就像您最后修改的日期一样。我不喜欢这样（$start和$end是PHP的DateTime对象）：
"DTSTART:".$start->setTimezone(new DateTimeZone('UTC'))->format('Ymd\THis\Z').$eol.
"DTEND:".$end->setTimezone(new DateTimeZone('UTC'))->format('Ymd\THis\Z')
所以，基本上，所有做的就是把日期为UTC时区，然后一个Z在结束格式化的日期/时间与客户沟通。
一个完整的工作示例（事件是有帮助的任何人）是：
<?php
date_default_timezone_set('America/New_York');
//CONFIGURE HERE
$fromName = "John Doe";
$fromEmail = "[email protected]";
$toName = "Your Name";
$toEmail = '[email protected]';
$start = new DateTime('2017-08-15 15:00');
$end = new DateTime('2017-08-15 16:00');
$summary = "Hello World Event";
//END CONFIGURATION
$uid = "";
$headers = array();
$boundary = "_CAL_" . uniqid("B",true) . "_B_";
$headers[] = "MIME-Version: 1.0";
$headers[] = "Content-Type: multipart/alternative; boundary=\"".$boundary."\"";
$headers[] = "To: \"{$toName}\" <{$toEmail}>";
$headers[] = "From: \"{$fromName}\" <{$fromEmail}>";
$calendarLines = array(
"BEGIN:VCALENDAR",
"METHOD:REQUEST",
"PRODID:-//PHP//MeetingRequest//EN",
"VERSION:2.0",
"BEGIN:VEVENT",
"ORGANIZER;CN={$fromName}:MAILTO:{$fromEmail}",
"ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN={$toName}:MAILTO:{$toEmail}",
"DESCRIPTION:{$summary}",
"SUMMARY:{$summary}",
"DTSTART:".$start->setTimezone(new DateTimeZone('UTC'))->format('Ymd\THis\Z'),
"DTEND:".$end->setTimezone(new DateTimeZone('UTC'))->format('Ymd\THis\Z'),
"UID:{$uid}",
"CLASS:PUBLIC",
"PRIORITY:5",
"DTSTAMP:".gmdate('Ymd\THis\Z'),
"TRANSP:OPAQUE",
"STATUS:CONFIRMED",
"SEQUENCE:0",
"LOCATION:123 Any Street",
"BEGIN:VALARM",
"ACTION:DISPLAY",
"DESCRIPTION:REMINDER",
"TRIGGER;RELATED=START:-PT15M",
"END:VALARM",
"END:VEVENT",
"END:VCALENDAR"
);
$calendarBase64 = base64_encode(implode("\r\n",$calendarLines));
//ensure we don't have lines longer than 70 characters for older computers:
$calendarResult = wordwrap($calendarBase64,68,"\n",true);
$emailLines = array(
"--{$boundary}",
"Content-Type: text/html; charset=\"iso - 8859 - 1\"",
"Content-Transfer-Encoding: quoted-printable",
"",
"<html><body>",
"<h1>Hello World</h1>",
"<p>This is a calendar event test</p>",
"</body></html>",
"",
"--{$boundary}",
"Content-Type: text/calendar; charset=\"utf - 8\"; method=REQUEST",
"Content-Transfer-Encoding: base64",
"",
$calendarResult,
"",
"--{$boundary}--"
);
$emailContent = implode("\n",$emailLines);
$headersResult = implode("\n",$headers);
mail($toEmail, $summary, $emailContent, $headersResult);
echo("<pre>".htmlentities($headersResult)."\n\n".htmlentities($emailContent)."</pre>");
echo("<br /><br />");
echo("<pre>".base64_decode($calendarResult)."</pre>");