[Calendar] Handle version timezone

lib/TimeZoneUtil.php

@@ -4,6 +4,7 @@
 
 use DateTimeZone;
 use InvalidArgumentException;
+use Sabre\VObject\TimezoneGuesser\FindFromMzVersionTimezone;
 use Sabre\VObject\TimezoneGuesser\FindFromOffset;
 use Sabre\VObject\TimezoneGuesser\FindFromOutlookCities;
 use Sabre\VObject\TimezoneGuesser\FindFromTimezoneIdentifier;
@@ -44,6 +45,7 @@ private function __construct()
         $this->addFinder('offset', new FindFromOffset());
         $this->addFinder('lowercase', new LowercaseTimezoneIdentifier());
         $this->addFinder('outlookCities', new FindFromOutlookCities());
+        $this->addFinder('version', new FindFromMzVersionTimezone());
     }
 
     private static function getInstance(): self

lib/TimezoneGuesser/FindFromMzVersionTimezone.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabre\VObject\TimezoneGuesser;
+
+use DateTimeZone;
+use Sabre\VObject\TimeZoneUtil;
+
+/**
+ * Try to ignore the trailing number of the Microsoft timezone.
+ *
+ * For example: Eastern Standard Time 1 => Eastern Standard Time
+ */
+class FindFromMzVersionTimezone implements TimezoneFinder
+{
+    public function find(string $tzid, bool $failIfUncertain = false): ?DateTimeZone
+    {
+        if (strlen($tzid) < 1) {
+            return null;
+        }
+
+        $trailingChar = (int) $tzid[strlen($tzid)-1];
+        if ($trailingChar <= 9 && $trailingChar >= 1) {
+            $tz = TimeZoneUtil::getTimeZone(substr($tzid, 0, strrpos($tzid, ' ')));
+            if ($tz->getName() === 'UTC') {
+                return null;
+            }
+
+            return $tz;
+        }
+
+        return null;
+    }
+}

tests/VObject/TimeZoneUtilTest.php

@@ -533,4 +533,29 @@ public function outlookCitiesProvider(): iterable
             'expected' => 'UTC',
         ];
     }
+
+    /**
+     * @dataProvider versionTzProvider
+     */
+    public function testVersionTz(string $origin, bool $failIfUncertain, string $expected)
+    {
+        $tz = TimeZoneUtil::getTimeZone($origin, null, $failIfUncertain);
+        $ex = new \DateTimeZone($expected);
+        $this->assertEquals($ex->getName(), $tz->getName());
+    }
+
+    public function versionTzProvider(): iterable
+    {
+        yield 'case 1' => [
+            'origin' => 'Eastern Standard Time 1',
+            'failIfUncertain' => true,
+            'expected' => 'America/New_York',
+        ];
+
+        yield 'case 2' => [
+            'origin' => 'Eastern Standard Time 2',
+            'failIfUncertain' => true,
+            'expected' => 'America/New_York',
+        ];
+    }
 }