diff --git a/apps/dav/appinfo/info.xml b/apps/dav/appinfo/info.xml
index 5cc374a566..6d801098c4 100644
--- a/apps/dav/appinfo/info.xml
+++ b/apps/dav/appinfo/info.xml
@@ -28,6 +28,7 @@
 	<repair-steps>
 		<post-migration>
 			<step>OCA\DAV\Migration\FixBirthdayCalendarComponent</step>
+			<step>OCA\DAV\Migration\RegenerateBirthdayCalendars</step>
 			<step>OCA\DAV\Migration\CalDAVRemoveEmptyValue</step>
 			<step>OCA\DAV\Migration\BuildCalendarSearchIndex</step>
 			<step>OCA\DAV\Migration\RefreshWebcalJobRegistrar</step>
diff --git a/apps/dav/composer/composer/autoload_classmap.php b/apps/dav/composer/composer/autoload_classmap.php
index 94e371037c..8bb2b077ed 100644
--- a/apps/dav/composer/composer/autoload_classmap.php
+++ b/apps/dav/composer/composer/autoload_classmap.php
@@ -159,6 +159,7 @@ return array(
     'OCA\\DAV\\Migration\\ChunkCleanup' => $baseDir . '/../lib/Migration/ChunkCleanup.php',
     'OCA\\DAV\\Migration\\FixBirthdayCalendarComponent' => $baseDir . '/../lib/Migration/FixBirthdayCalendarComponent.php',
     'OCA\\DAV\\Migration\\RefreshWebcalJobRegistrar' => $baseDir . '/../lib/Migration/RefreshWebcalJobRegistrar.php',
+    'OCA\\DAV\\Migration\\RegenerateBirthdayCalendars' => $baseDir . '/../lib/Migration/RegenerateBirthdayCalendars.php',
     'OCA\\DAV\\Migration\\RemoveClassifiedEventActivity' => $baseDir . '/../lib/Migration/RemoveClassifiedEventActivity.php',
     'OCA\\DAV\\Migration\\RemoveOrphanEventsAndContacts' => $baseDir . '/../lib/Migration/RemoveOrphanEventsAndContacts.php',
     'OCA\\DAV\\Migration\\Version1004Date20170825134824' => $baseDir . '/../lib/Migration/Version1004Date20170825134824.php',
diff --git a/apps/dav/composer/composer/autoload_static.php b/apps/dav/composer/composer/autoload_static.php
index fb3de390d6..e4b69b5a74 100644
--- a/apps/dav/composer/composer/autoload_static.php
+++ b/apps/dav/composer/composer/autoload_static.php
@@ -174,6 +174,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Migration\\ChunkCleanup' => __DIR__ . '/..' . '/../lib/Migration/ChunkCleanup.php',
         'OCA\\DAV\\Migration\\FixBirthdayCalendarComponent' => __DIR__ . '/..' . '/../lib/Migration/FixBirthdayCalendarComponent.php',
         'OCA\\DAV\\Migration\\RefreshWebcalJobRegistrar' => __DIR__ . '/..' . '/../lib/Migration/RefreshWebcalJobRegistrar.php',
+        'OCA\\DAV\\Migration\\RegenerateBirthdayCalendars' => __DIR__ . '/..' . '/../lib/Migration/RegenerateBirthdayCalendars.php',
         'OCA\\DAV\\Migration\\RemoveClassifiedEventActivity' => __DIR__ . '/..' . '/../lib/Migration/RemoveClassifiedEventActivity.php',
         'OCA\\DAV\\Migration\\RemoveOrphanEventsAndContacts' => __DIR__ . '/..' . '/../lib/Migration/RemoveOrphanEventsAndContacts.php',
         'OCA\\DAV\\Migration\\Version1004Date20170825134824' => __DIR__ . '/..' . '/../lib/Migration/Version1004Date20170825134824.php',
diff --git a/apps/dav/lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php b/apps/dav/lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php
index c4279c5108..dd6fca73c8 100644
--- a/apps/dav/lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php
+++ b/apps/dav/lib/BackgroundJob/GenerateBirthdayCalendarBackgroundJob.php
@@ -51,6 +51,7 @@ class GenerateBirthdayCalendarBackgroundJob extends QueuedJob {
 	 */
 	public function run($arguments) {
 		$userId = $arguments['userId'];
+		$purgeBeforeGenerating = $arguments['purgeBeforeGenerating'] ?? false;
 
 		// make sure admin didn't change his mind
 		$isGloballyEnabled = $this->config->getAppValue('dav', 'generateBirthdayCalendar', 'yes');
@@ -64,6 +65,10 @@ class GenerateBirthdayCalendarBackgroundJob extends QueuedJob {
 			return;
 		}
 
+		if ($purgeBeforeGenerating) {
+			$this->birthdayService->resetForUser($userId);
+		}
+
 		$this->birthdayService->syncUser($userId);
 	}
 }
diff --git a/apps/dav/lib/CalDAV/BirthdayService.php b/apps/dav/lib/CalDAV/BirthdayService.php
index 0f6e819bcc..0e8926e775 100644
--- a/apps/dav/lib/CalDAV/BirthdayService.php
+++ b/apps/dav/lib/CalDAV/BirthdayService.php
@@ -32,6 +32,7 @@ use Exception;
 use OCA\DAV\CardDAV\CardDavBackend;
 use OCA\DAV\DAV\GroupPrincipalBackend;
 use OCP\IConfig;
+use OCP\IDBConnection;
 use Sabre\VObject\Component\VCalendar;
 use Sabre\VObject\Component\VCard;
 use Sabre\VObject\DateTimeParser;
@@ -56,6 +57,9 @@ class BirthdayService {
 	/** @var IConfig */
 	private $config;
 
+	/** @var IDBConnection */
+	private $dbConnection;
+
 	/**
 	 * BirthdayService constructor.
 	 *
@@ -64,11 +68,12 @@ class BirthdayService {
 	 * @param GroupPrincipalBackend $principalBackend
 	 * @param IConfig $config;
 	 */
-	public function __construct(CalDavBackend $calDavBackEnd, CardDavBackend $cardDavBackEnd, GroupPrincipalBackend $principalBackend, IConfig $config) {
+	public function __construct(CalDavBackend $calDavBackEnd, CardDavBackend $cardDavBackEnd, GroupPrincipalBackend $principalBackend, IConfig $config, IDBConnection $dbConnection) {
 		$this->calDavBackEnd = $calDavBackEnd;
 		$this->cardDavBackEnd = $cardDavBackEnd;
 		$this->principalBackend = $principalBackend;
 		$this->config = $config;
+		$this->dbConnection = $dbConnection;
 	}
 
 	/**
@@ -85,9 +90,9 @@ class BirthdayService {
 		$book = $this->cardDavBackEnd->getAddressBookById($addressBookId);
 		$targetPrincipals[] = $book['principaluri'];
 		$datesToSync = [
-			['postfix' => '', 'field' => 'BDAY', 'symbol' => '*'],
-			['postfix' => '-death', 'field' => 'DEATHDATE', 'symbol' => "†"],
-			['postfix' => '-anniversary', 'field' => 'ANNIVERSARY', 'symbol' => "⚭"],
+			['postfix' => '', 'field' => 'BDAY', 'symbol' => '*', 'utfSymbol' => '🎂'],
+			['postfix' => '-death', 'field' => 'DEATHDATE', 'symbol' => "†", 'utfSymbol' => '⚰️'],
+			['postfix' => '-anniversary', 'field' => 'ANNIVERSARY', 'symbol' => "⚭", 'utfSymbol' => '💍'],
 		];
 		foreach ($targetPrincipals as $principalUri) {
 			if (!$this->isUserEnabled($principalUri)) {
@@ -132,9 +137,9 @@ class BirthdayService {
 	 * @throws \Sabre\DAV\Exception\BadRequest
 	 */
 	public function ensureCalendarExists($principal) {
-		$book = $this->calDavBackEnd->getCalendarByUri($principal, self::BIRTHDAY_CALENDAR_URI);
-		if (!is_null($book)) {
-			return $book;
+		$calendar = $this->calDavBackEnd->getCalendarByUri($principal, self::BIRTHDAY_CALENDAR_URI);
+		if (!is_null($calendar)) {
+			return $calendar;
 		}
 		$this->calDavBackEnd->createCalendar($principal, self::BIRTHDAY_CALENDAR_URI, [
 			'{DAV:}displayname' => 'Contact birthdays',
@@ -150,9 +155,10 @@ class BirthdayService {
 	 * @param string $dateField
 	 * @param string $postfix
 	 * @param string $summarySymbol
+	 * @param string $utfSummarySymbol
 	 * @return null|VCalendar
 	 */
-	public function buildDateFromContact($cardData, $dateField, $postfix, $summarySymbol) {
+	public function buildDateFromContact($cardData, $dateField, $postfix, $summarySymbol, $utfSummarySymbol) {
 		if (empty($cardData)) {
 			return null;
 		}
@@ -191,10 +197,26 @@ class BirthdayService {
 		}
 
 		$unknownYear = false;
+		$originalYear = null;
 		if (!$dateParts['year']) {
-			$birthday = '1900-' . $dateParts['month'] . '-' . $dateParts['date'];
+			$birthday = '1970-' . $dateParts['month'] . '-' . $dateParts['date'];
 
 			$unknownYear = true;
+		} else {
+			$parameters = $birthday->parameters();
+			if (isset($parameters['X-APPLE-OMIT-YEAR'])) {
+				$omitYear = $parameters['X-APPLE-OMIT-YEAR'];
+				if ($dateParts['year'] === $omitYear) {
+					$birthday = '1970-' . $dateParts['month'] . '-' . $dateParts['date'];
+					$unknownYear = true;
+				}
+			} else {
+				$originalYear = (int)$dateParts['year'];
+
+				if ($originalYear < 1970) {
+					$birthday = '1970-' . $dateParts['month'] . '-' . $dateParts['date'];
+				}
+			}
 		}
 
 		try {
@@ -202,12 +224,20 @@ class BirthdayService {
 		} catch (Exception $e) {
 			return null;
 		}
-		if ($unknownYear) {
-			$summary = $doc->FN->getValue() . ' ' . $summarySymbol;
+		if ($this->dbConnection->supports4ByteText()) {
+			if ($unknownYear) {
+				$summary = $utfSummarySymbol . ' ' . $doc->FN->getValue();
+			} else {
+				$summary = $utfSummarySymbol . ' ' . $doc->FN->getValue() . " ($originalYear)";
+			}
 		} else {
-			$year = (int)$date->format('Y');
-			$summary = $doc->FN->getValue() . " ($summarySymbol$year)";
+			if ($unknownYear) {
+				$summary = $doc->FN->getValue() . ' ' . $summarySymbol;
+			} else {
+				$summary = $doc->FN->getValue() . " ($summarySymbol$originalYear)";
+			}
 		}
+
 		$vCal = new VCalendar();
 		$vCal->VERSION = '2.0';
 		$vEvent = $vCal->createComponent('VEVENT');
@@ -226,6 +256,11 @@ class BirthdayService {
 		$vEvent->{'RRULE'} = 'FREQ=YEARLY';
 		$vEvent->{'SUMMARY'} = $summary;
 		$vEvent->{'TRANSP'} = 'TRANSPARENT';
+		$vEvent->{'X-NEXTCLOUD-BC-FIELD-TYPE'} = $dateField;
+		$vEvent->{'X-NEXTCLOUD-BC-UNKNOWN-YEAR'} = $unknownYear ? '1' : '0';
+		if ($originalYear !== null) {
+			$vEvent->{'X-NEXTCLOUD-BC-YEAR'} = (string) $originalYear;
+		}
 		$alarm = $vCal->createComponent('VALARM');
 		$alarm->add($vCal->createProperty('TRIGGER', '-PT0M', ['VALUE' => 'DURATION']));
 		$alarm->add($vCal->createProperty('ACTION', 'DISPLAY'));
@@ -235,6 +270,19 @@ class BirthdayService {
 		return $vCal;
 	}
 
+	/**
+	 * @param string $user
+	 */
+	public function resetForUser($user) {
+		$principal = 'principals/users/'.$user;
+		$calendar = $this->calDavBackEnd->getCalendarByUri($principal, self::BIRTHDAY_CALENDAR_URI);
+		$calendarObjects = $this->calDavBackEnd->getCalendarObjects($calendar['id'], CalDavBackend::CALENDAR_TYPE_CALENDAR);
+
+		foreach($calendarObjects as $calendarObject) {
+			$this->calDavBackEnd->deleteCalendarObject($calendar['id'], $calendarObject['uri'], CalDavBackend::CALENDAR_TYPE_CALENDAR);
+		}
+	}
+
 	/**
 	 * @param string $user
 	 */
@@ -298,7 +346,7 @@ class BirthdayService {
 	 */
 	private function updateCalendar($cardUri, $cardData, $book, $calendarId, $type) {
 		$objectUri = $book['uri'] . '-' . $cardUri . $type['postfix'] . '.ics';
-		$calendarData = $this->buildDateFromContact($cardData, $type['field'], $type['postfix'], $type['symbol']);
+		$calendarData = $this->buildDateFromContact($cardData, $type['field'], $type['postfix'], $type['symbol'], $type['utfSymbol']);
 		$existing = $this->calDavBackEnd->getCalendarObject($calendarId, $objectUri);
 		if (is_null($calendarData)) {
 			if (!is_null($existing)) {
diff --git a/apps/dav/lib/Migration/RegenerateBirthdayCalendars.php b/apps/dav/lib/Migration/RegenerateBirthdayCalendars.php
new file mode 100644
index 0000000000..2c2b4eb0e9
--- /dev/null
+++ b/apps/dav/lib/Migration/RegenerateBirthdayCalendars.php
@@ -0,0 +1,85 @@
+<?php
+/**
+ * @copyright 2019 Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\DAV\Migration;
+
+use OCA\DAV\BackgroundJob\GenerateBirthdayCalendarBackgroundJob;
+use OCP\BackgroundJob\IJobList;
+use OCP\IConfig;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Migration\IOutput;
+use OCP\Migration\IRepairStep;
+
+class RegenerateBirthdayCalendars implements IRepairStep {
+
+	/** @var IUserManager */
+	private $userManager;
+
+	/** @var IJobList */
+	private $jobList;
+
+	/** @var IConfig */
+	private $config;
+
+	/**
+	 * @param IUserManager $userManager,
+	 * @param IJobList $jobList
+	 * @param IConfig $config
+	 */
+	public function __construct(IUserManager $userManager,
+								IJobList $jobList,
+								IConfig $config) {
+		$this->userManager = $userManager;
+		$this->jobList = $jobList;
+		$this->config = $config;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getName() {
+		return 'Regenerating birthday calendars to use new icons and fix old birthday events without year';
+	}
+
+	/**
+	 * @param IOutput $output
+	 */
+	public function run(IOutput $output) {
+		// only run once
+		if ($this->config->getAppValue('dav', 'regeneratedBirthdayCalendarsForYearFix') === 'yes') {
+			$output->info('Repair step already executed');
+			return;
+		}
+
+		$output->info('Adding background jobs to regenerate birthday calendar');
+		$this->userManager->callForAllUsers(function(IUser $user) {
+			$this->jobList->add(GenerateBirthdayCalendarBackgroundJob::class, [
+				'userId' => $user->getUID(),
+				'purgeBeforeGenerating' => true
+			]);
+		});
+
+		// if all were done, no need to redo the repair during next upgrade
+		$this->config->setAppValue('dav', 'regeneratedBirthdayCalendarsForYearFix', 'yes');
+	}
+}
\ No newline at end of file
diff --git a/apps/dav/tests/unit/BackgroundJob/GenerateBirthdayCalendarBackgroundJobTest.php b/apps/dav/tests/unit/BackgroundJob/GenerateBirthdayCalendarBackgroundJobTest.php
index 010289a745..1d672ff22a 100644
--- a/apps/dav/tests/unit/BackgroundJob/GenerateBirthdayCalendarBackgroundJobTest.php
+++ b/apps/dav/tests/unit/BackgroundJob/GenerateBirthdayCalendarBackgroundJobTest.php
@@ -62,6 +62,10 @@ class GenerateBirthdayCalendarBackgroundJobTest extends TestCase {
 			->with('user123', 'dav', 'generateBirthdayCalendar', 'yes')
 			->will($this->returnValue('yes'));
 
+		$this->birthdayService->expects($this->never())
+			->method('resetForUser')
+			->with('user123');
+
 		$this->birthdayService->expects($this->once())
 			->method('syncUser')
 			->with('user123');
@@ -69,6 +73,28 @@ class GenerateBirthdayCalendarBackgroundJobTest extends TestCase {
 		$this->backgroundJob->run(['userId' => 'user123']);
 	}
 
+	public function testRunAndReset() {
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('dav', 'generateBirthdayCalendar', 'yes')
+			->will($this->returnValue('yes'));
+
+		$this->config->expects($this->once())
+			->method('getUserValue')
+			->with('user123', 'dav', 'generateBirthdayCalendar', 'yes')
+			->will($this->returnValue('yes'));
+
+		$this->birthdayService->expects($this->once())
+			->method('resetForUser')
+			->with('user123');
+
+		$this->birthdayService->expects($this->once())
+			->method('syncUser')
+			->with('user123');
+
+		$this->backgroundJob->run(['userId' => 'user123', 'purgeBeforeGenerating' => true]);
+	}
+
 	public function testRunGloballyDisabled() {
 		$this->config->expects($this->once())
 			->method('getAppValue')
diff --git a/apps/dav/tests/unit/CardDAV/BirthdayServiceTest.php b/apps/dav/tests/unit/CardDAV/BirthdayServiceTest.php
index 651fbf5eaf..46aa06e853 100644
--- a/apps/dav/tests/unit/CardDAV/BirthdayServiceTest.php
+++ b/apps/dav/tests/unit/CardDAV/BirthdayServiceTest.php
@@ -29,6 +29,7 @@ use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CardDAV\CardDavBackend;
 use OCA\DAV\DAV\GroupPrincipalBackend;
 use OCP\IConfig;
+use OCP\IDBConnection;
 use Sabre\VObject\Component\VCalendar;
 use Sabre\VObject\Reader;
 use Test\TestCase;
@@ -45,6 +46,8 @@ class BirthdayServiceTest extends TestCase {
 	private $groupPrincipalBackend;
 	/** @var IConfig | \PHPUnit_Framework_MockObject_MockObject */
 	private $config;
+	/** @var IDBConnection | \PHPUnit_Framework_MockObject_MockObject */
+	private $dbConnection;
 
 	public function setUp() {
 		parent::setUp();
@@ -53,18 +56,25 @@ class BirthdayServiceTest extends TestCase {
 		$this->cardDav = $this->createMock(CardDavBackend::class);
 		$this->groupPrincipalBackend = $this->createMock(GroupPrincipalBackend::class);
 		$this->config = $this->createMock(IConfig::class);
+		$this->dbConnection = $this->createMock(IDBConnection::class);
 
 		$this->service = new BirthdayService($this->calDav, $this->cardDav,
-			$this->groupPrincipalBackend, $this->config);
+			$this->groupPrincipalBackend, $this->config, $this->dbConnection);
 	}
 
 	/**
 	 * @dataProvider providesVCards
-	 * @param boolean $expectedSummary
+	 * @param string $expectedSummary
+	 * @param string $expectedDTStart
+	 * @param string $expectedFieldType
+	 * @param string $expectedUnknownYear
+	 * @param string $expectedOriginalYear
 	 * @param string | null $data
 	 */
-	public function testBuildBirthdayFromContact($expectedSummary, $data) {
-		$cal = $this->service->buildDateFromContact($data, 'BDAY', '', '*');
+	public function testBuildBirthdayFromContact($expectedSummary, $expectedDTStart, $expectedFieldType, $expectedUnknownYear, $expectedOriginalYear, $data, $supports4Bytes) {
+		$this->dbConnection->method('supports4ByteText')->willReturn($supports4Bytes);
+		$cal = $this->service->buildDateFromContact($data, 'BDAY', '', '*', '🎂');
+
 		if ($expectedSummary === null) {
 			$this->assertNull($cal);
 		} else {
@@ -72,6 +82,14 @@ class BirthdayServiceTest extends TestCase {
 			$this->assertTrue(isset($cal->VEVENT));
 			$this->assertEquals('FREQ=YEARLY', $cal->VEVENT->RRULE->getValue());
 			$this->assertEquals($expectedSummary, $cal->VEVENT->SUMMARY->getValue());
+			$this->assertEquals($expectedDTStart, $cal->VEVENT->DTSTART->getValue());
+			$this->assertEquals($expectedFieldType, $cal->VEVENT->{'X-NEXTCLOUD-BC-FIELD-TYPE'}->getValue());
+			$this->assertEquals($expectedUnknownYear, $cal->VEVENT->{'X-NEXTCLOUD-BC-UNKNOWN-YEAR'}->getValue());
+
+			if ($expectedOriginalYear) {
+				$this->assertEquals($expectedOriginalYear, $cal->VEVENT->{'X-NEXTCLOUD-BC-YEAR'}->getValue());
+			}
+
 			$this->assertEquals('TRANSPARENT', $cal->VEVENT->TRANSP->getValue());
 		}
 	}
@@ -151,7 +169,7 @@ class BirthdayServiceTest extends TestCase {
 
 		$service = $this->getMockBuilder(BirthdayService::class)
 			->setMethods(['buildDateFromContact', 'birthdayEvenChanged'])
-			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config])
+			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config, $this->dbConnection])
 			->getMock();
 
 		$service->onCardChanged(666, 'gump.vcf', '');
@@ -180,7 +198,7 @@ class BirthdayServiceTest extends TestCase {
 		/** @var BirthdayService | \PHPUnit_Framework_MockObject_MockObject $service */
 		$service = $this->getMockBuilder(BirthdayService::class)
 			->setMethods(['buildDateFromContact', 'birthdayEvenChanged'])
-			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config])
+			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config, $this->dbConnection])
 			->getMock();
 
 		$service->onCardChanged(666, 'gump.vcf', '');
@@ -216,7 +234,7 @@ class BirthdayServiceTest extends TestCase {
 		/** @var BirthdayService | \PHPUnit_Framework_MockObject_MockObject $service */
 		$service = $this->getMockBuilder(BirthdayService::class)
 			->setMethods(['buildDateFromContact', 'birthdayEvenChanged'])
-			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config])
+			->setConstructorArgs([$this->calDav, $this->cardDav, $this->groupPrincipalBackend, $this->config, $this->dbConnection])
 			->getMock();
 
 		if ($expectedOp === 'delete') {
@@ -311,6 +329,32 @@ class BirthdayServiceTest extends TestCase {
 		$this->service->ensureCalendarExists('principal001');
 	}
 
+	public function testResetForUser() {
+		$this->calDav->expects($this->at(0))
+			->method('getCalendarByUri')
+			->with('principals/users/user123', 'contact_birthdays')
+			->willReturn(['id' => 42]);
+
+		$this->calDav->expects($this->at(1))
+			->method('getCalendarObjects')
+			->with(42, 0)
+			->willReturn([['uri' => '1.ics'], ['uri' => '2.ics'], ['uri' => '3.ics']]);
+
+		$this->calDav->expects($this->at(2))
+			->method('deleteCalendarObject')
+			->with(42, '1.ics', 0);
+
+		$this->calDav->expects($this->at(3))
+			->method('deleteCalendarObject')
+			->with(42, '2.ics', 0);
+
+		$this->calDav->expects($this->at(4))
+			->method('deleteCalendarObject')
+			->with(42, '3.ics', 0);
+
+		$this->service->resetForUser('user123');
+	}
+
 	public function providesBirthday() {
 		return [
 			[true,
@@ -338,19 +382,27 @@ class BirthdayServiceTest extends TestCase {
 
 	public function providesVCards() {
 		return [
-			[null, null],
-			[null, ''],
-			[null, 'yasfewf'],
-			[null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			[null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			[null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:someday\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			['12345 (*1900)', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19000101\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			['12345 (*1900)', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19001231\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			['12345 *', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:--1231\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			['12345 *', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY;X-APPLE-OMIT-YEAR=1604:16041231\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			[null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:;VALUE=text:circa 1800\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			[null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nN:12345;;;;\r\nBDAY:20031231\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
-			['12345 (*900)', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:09001231\r\nEND:VCARD\r\n", "Dr. Foo Bar"],
+			// $expectedSummary, $expectedDTStart, $expectedFieldType, $expectedUnknownYear, $expectedOriginalYear, $data, $supports4Byte
+			[null, null, null, null, null, null, true],
+			[null, null, null, null, null, '', true],
+			[null, null, null, null, null, 'yasfewf', true],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nEND:VCARD\r\n", true],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:\r\nEND:VCARD\r\n", true],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:someday\r\nEND:VCARD\r\n", true],
+			['🎂 12345 (1900)', '19700101', 'BDAY', '0', '1900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19000101\r\nEND:VCARD\r\n", true],
+			['🎂 12345 (1900)', '19701231', 'BDAY', '0', '1900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19001231\r\nEND:VCARD\r\n", true],
+			['🎂 12345', '19701231', 'BDAY', '1', null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:--1231\r\nEND:VCARD\r\n", true],
+			['🎂 12345', '19701231', 'BDAY', '1', null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY;X-APPLE-OMIT-YEAR=1604:16041231\r\nEND:VCARD\r\n", true],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:;VALUE=text:circa 1800\r\nEND:VCARD\r\n", true],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nN:12345;;;;\r\nBDAY:20031231\r\nEND:VCARD\r\n", true],
+			['🎂 12345 (900)', '19701231', 'BDAY', '0', '900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:09001231\r\nEND:VCARD\r\n", true],
+			['12345 (*1900)', '19700101', 'BDAY', '0', '1900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19000101\r\nEND:VCARD\r\n", false],
+			['12345 (*1900)', '19701231', 'BDAY', '0', '1900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:19001231\r\nEND:VCARD\r\n", false],
+			['12345 *', '19701231', 'BDAY', '1', null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:--1231\r\nEND:VCARD\r\n", false],
+			['12345 *', '19701231', 'BDAY', '1', null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY;X-APPLE-OMIT-YEAR=1604:16041231\r\nEND:VCARD\r\n", false],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:;VALUE=text:circa 1800\r\nEND:VCARD\r\n", false],
+			[null, null, null, null, null, "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nN:12345;;;;\r\nBDAY:20031231\r\nEND:VCARD\r\n",  false],
+			['12345 (*900)', '19701231', 'BDAY', '0', '900', "BEGIN:VCARD\r\nVERSION:3.0\r\nPRODID:-//Sabre//Sabre VObject 4.1.1//EN\r\nUID:12345\r\nFN:12345\r\nN:12345;;;;\r\nBDAY:09001231\r\nEND:VCARD\r\n", false],
 		];
 	}
 }
diff --git a/apps/dav/tests/unit/Migration/RegenerateBirthdayCalendarsTest.php b/apps/dav/tests/unit/Migration/RegenerateBirthdayCalendarsTest.php
new file mode 100644
index 0000000000..05e12bbda6
--- /dev/null
+++ b/apps/dav/tests/unit/Migration/RegenerateBirthdayCalendarsTest.php
@@ -0,0 +1,137 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\DAV\Tests\unit\DAV\Migration;
+
+use OCA\DAV\BackgroundJob\GenerateBirthdayCalendarBackgroundJob;
+use OCA\DAV\Migration\RefreshWebcalJobRegistrar;
+use OCA\DAV\Migration\RegenerateBirthdayCalendars;
+use OCP\BackgroundJob\IJobList;
+use OCP\IConfig;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\Migration\IOutput;
+use Test\TestCase;
+
+class RegenerateBirthdayCalendarsTest extends TestCase {
+
+	/** @var IUserManager | \PHPUnit_Framework_MockObject_MockObject */
+	private $userManager;
+
+	/** @var IJobList | \PHPUnit_Framework_MockObject_MockObject */
+	private $jobList;
+
+	/** @var IConfig | \PHPUnit_Framework_MockObject_MockObject */
+	private $config;
+
+	/** @var RefreshWebcalJobRegistrar */
+	private $migration;
+
+	protected function setUp() {
+		parent::setUp();
+
+		$this->userManager = $this->createMock(IUserManager::class);
+		$this->jobList = $this->createMock(IJobList::class);
+		$this->config = $this->createMock(IConfig::class);
+
+		$this->migration = new RegenerateBirthdayCalendars($this->userManager,
+			$this->jobList, $this->config);
+	}
+
+	public function testGetName() {
+		$this->assertEquals(
+			'Regenerating birthday calendars to use new icons and fix old birthday events without year',
+			$this->migration->getName()
+		);
+	}
+
+	public function testRun() {
+		$this->config->expects($this->at(0))
+			->method('getAppValue')
+			->with('dav', 'regeneratedBirthdayCalendarsForYearFix')
+			->willReturn(null);
+
+		$output = $this->createMock(IOutput::class);
+		$output->expects($this->once())
+			->method('info')
+			->with('Adding background jobs to regenerate birthday calendar');
+
+		$this->userManager->expects($this->once())
+			->method('callForAllUsers')
+			->will($this->returnCallback(function($closure) {
+				$user1 = $this->createMock(IUser::class);
+				$user1->method('getUID')->will($this->returnValue('uid1'));
+				$user2 = $this->createMock(IUser::class);
+				$user2->method('getUID')->will($this->returnValue('uid2'));
+				$user3 = $this->createMock(IUser::class);
+				$user3->method('getUID')->will($this->returnValue('uid3'));
+
+				$closure($user1);
+				$closure($user2);
+				$closure($user3);
+			}));
+
+		$this->jobList->expects($this->at(0))
+			->method('add')
+			->with(GenerateBirthdayCalendarBackgroundJob::class, [
+				'userId' => 'uid1',
+				'purgeBeforeGenerating' => true
+			]);
+		$this->jobList->expects($this->at(1))
+			->method('add')
+			->with(GenerateBirthdayCalendarBackgroundJob::class, [
+				'userId' => 'uid2',
+				'purgeBeforeGenerating' => true
+			]);
+		$this->jobList->expects($this->at(2))
+			->method('add')
+			->with(GenerateBirthdayCalendarBackgroundJob::class, [
+				'userId' => 'uid3',
+				'purgeBeforeGenerating' => true
+			]);
+
+		$this->config->expects($this->at(1))
+			->method('setAppValue')
+			->with('dav', 'regeneratedBirthdayCalendarsForYearFix', 'yes');
+
+		$this->migration->run($output);
+	}
+
+	public function testRunSecondTime() {
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('dav', 'regeneratedBirthdayCalendarsForYearFix')
+			->willReturn('yes');
+
+		$output = $this->createMock(IOutput::class);
+		$output->expects($this->once())
+			->method('info')
+			->with('Repair step already executed');
+
+		$this->userManager->expects($this->never())
+			->method('callForAllUsers');
+
+		$this->migration->run($output);
+	}
+
+
+}
\ No newline at end of file