diff --git a/test/php/Lib/FakeReportData.php b/test/php/Lib/FakeReportData.php
new file mode 100644
index 000000000..756da1929
--- /dev/null
+++ b/test/php/Lib/FakeReportData.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Tests\Icinga\Module\Icingadb\Lib;
+
+use Icinga\Module\Icingadb\ProvidedHook\Reporting\Common\SlaTimelines;
+
+class FakeReportData
+{
+    use SlaTimelines;
+
+    public function setDimensions(array $_)
+    {
+    }
+
+    public function getDimensions()
+    {
+        return [];
+    }
+
+    public function setRows(array $rows)
+    {
+    }
+}
diff --git a/test/php/Lib/SlaReportWithCustomDb.php b/test/php/Lib/SlaReportWithCustomDb.php
new file mode 100644
index 000000000..24fc4cfc7
--- /dev/null
+++ b/test/php/Lib/SlaReportWithCustomDb.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace Tests\Icinga\Module\Icingadb\Lib;
+
+use DateTime;
+use Icinga\Module\Icingadb\ProvidedHook\Reporting\Common\SlaReportUtils;
+use Icinga\Module\Icingadb\ProvidedHook\Reporting\Common\SlaTimeline;
+use ipl\Sql\Connection;
+
+class SlaReportWithCustomDb
+{
+    use SlaReportUtils;
+
+    /** @var Connection */
+    protected static $conn;
+
+    protected $reportType;
+
+    protected static $dbConfiguration = [
+        'mysql' => [
+            'db'        => 'mysql',
+            'host'      => '127.0.0.1',
+            'port'      => 3306,
+            'dbname'    => 'icingadb_web_unittest',
+            'username'  => 'icingadb_web_unittest',
+            'password'  => 'icingadb_web_unittest'
+        ]
+    ];
+
+    public function resetConn()
+    {
+        static::$conn = null;
+    }
+
+    public function getDb(): Connection
+    {
+        if (! static::$conn) {
+            $config = static::$dbConfiguration['mysql'];
+            $host = getenv('ICINGADBWEB_TEST_MYSQL_HOST');
+            if ($host) {
+                $config['host'] = $host;
+            }
+
+            $port = getenv('ICINGADBWEB_TEST_MYSQL_PORT');
+            if ($port) {
+                $config['port'] = $port;
+            }
+
+            static::$conn = new Connection($config);
+            $fixtures = file_get_contents(__DIR__ . '/fixtures.sql');
+            static::$conn->exec($fixtures);
+        }
+
+        return static::$conn;
+    }
+
+    public function getReportType(): string
+    {
+        return $this->reportType;
+    }
+
+    public function getSlaTimeline(DateTime $start, DateTime $end, string $type, string $id): SlaTimeline
+    {
+        $this->reportType = $type;
+
+        return $this->fetchReportData($start, $end, ['filter' => null])->getTimelines(bin2hex($id))[0];
+    }
+
+    protected function createReportData()
+    {
+        return new FakeReportData();
+    }
+
+    protected function createReportRow($_)
+    {
+        return 'NOPE!';
+    }
+}
diff --git a/test/php/Lib/fixtures.sql b/test/php/Lib/fixtures.sql
new file mode 100644
index 000000000..7c08dcd8c
--- /dev/null
+++ b/test/php/Lib/fixtures.sql
@@ -0,0 +1,55 @@
+CREATE TABLE host (
+    id binary(20) NOT NULL PRIMARY KEY,
+    display_name varchar(254) NOT NULL
+);
+
+CREATE TABLE host_state (
+    id binary(20) NOT NULL,
+    host_id binary(20) NOT NULL,
+    hard_state TINYINT UNSIGNED NOT NULL,
+    previous_hard_state TINYINT UNSIGNED DEFAULT NULL,
+
+    PRIMARY KEY(id, host_id)
+);
+
+CREATE TABLE service (
+    id binary(20) NOT NULL,
+    host_id binary(20) NOT NULL,
+    display_name varchar(254) NOT NULL,
+
+    PRIMARY KEY(id, host_id)
+);
+
+CREATE TABLE service_state (
+    id binary(20) NOT NULL PRIMARY KEY,
+    host_id binary(20) NOT NULL,
+    service_id binary(20) NOT NULL,
+    hard_state TINYINT UNSIGNED NOT NULL,
+    previous_hard_state TINYINT UNSIGNED DEFAULT NULL
+);
+
+CREATE TABLE sla_history_state (
+    id binary(20) NOT NULL PRIMARY KEY,
+    environment_id binary(20) DEFAULT NULL,
+    endpoint_id binary(20) DEFAULT NULL,
+    object_type enum('host', 'service') NOT NULL,
+    host_id binary(20) NOT NULL,
+    service_id binary(20) DEFAULT NULL,
+
+    event_time bigint unsigned NOT NULL,
+    hard_state TINYINT UNSIGNED NOT NULL,
+    previous_hard_state TINYINT UNSIGNED NOT NULL
+);
+
+CREATE TABLE sla_history_downtime (
+    id binary(20) NOT NULL PRIMARY KEY,
+    environment_id binary(20) DEFAULT NULL,
+    endpoint_id binary(20) DEFAULT NULL,
+    object_type enum('host', 'service') NOT NULL,
+    host_id binary(20) NOT NULL,
+    service_id binary(20) DEFAULT NULL,
+
+    downtime_id binary(20) NOT NULL,
+    downtime_start BIGINT UNSIGNED NOT NULL,
+    downtime_end BIGINT UNSIGNED NOT NULL
+);
diff --git a/test/php/library/Icingadb/ProvidedHook/Reporting/SlaTest.php b/test/php/library/Icingadb/ProvidedHook/Reporting/SlaTest.php
new file mode 100644
index 000000000..fd7bf5fcf
--- /dev/null
+++ b/test/php/library/Icingadb/ProvidedHook/Reporting/SlaTest.php
@@ -0,0 +1,339 @@
+<?php
+
+namespace Tests\Icinga\Modules\Icingadb\ProvidedHook\Reporting;
+
+use DateTime;
+use ipl\Sql\Connection;
+use PHPUnit\Framework\TestCase;
+use Tests\Icinga\Module\Icingadb\Lib\SlaReportWithCustomDb;
+
+class SlaTest extends TestCase
+{
+    /** @var SlaReportWithCustomDb */
+    protected $report;
+
+    /** @var Connection */
+    protected $conn;
+
+    protected $hostId;
+
+    protected $serviceId;
+
+    /** @var DateTime */
+    protected $start;
+
+    /** @var DateTime */
+    protected $end;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->report = new SlaReportWithCustomDb();
+        $this->conn = $this->report->getDb();
+
+        $this->start = (new DateTime())->setTimestamp(1000);
+        $this->end = (new DateTime())->setTimestamp(2000);
+
+        $this->insertHostAndService();
+    }
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+
+        $this->conn->exec('DROP TABLE IF EXISTS host');
+        $this->conn->exec('DROP TABLE IF EXISTS host_state');
+        $this->conn->exec('DROP TABLE IF EXISTS service');
+        $this->conn->exec('DROP TABLE IF EXISTS service_state');
+        $this->conn->exec('DROP TABLE IF EXISTS sla_history_state');
+        $this->conn->exec('DROP TABLE IF EXISTS sla_history_downtime');
+
+        $this->report->resetConn();
+    }
+
+    public function testEmptyHistoryEvents()
+    {
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(100.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(100.0, $timeline->getResult());
+    }
+
+    public function testMultipleStateChanges()
+    {
+        $this->insertSlaHistoryEvents([
+            'state' => [
+                ['event_time' => 1000000, 'hard_state' => 2, 'previous_hard_state' => 99], // -10%
+                ['event_time' => 1100000, 'hard_state' => 0, 'previous_hard_state' => 2], // OK
+                ['event_time' => 1300000, 'hard_state' => 2, 'previous_hard_state' => 0], // -10%
+                ['event_time' => 1400000, 'hard_state' => 0, 'previous_hard_state' => 2], // OK
+                ['event_time' => 1600000, 'hard_state' => 2, 'previous_hard_state' => 0], // -10%
+                ['event_time' => 1700000, 'hard_state' => 0, 'previous_hard_state' => 2], // OK
+                ['event_time' => 1900000, 'hard_state' => 2, 'previous_hard_state' => 0], // -10%
+            ]
+        ]);
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(60.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(60.0, $timeline->getResult());
+    }
+
+    public function testOverlappingDowntimesAndProblems()
+    {
+        $this->insertSlaHistoryEvents([
+            'state'    => [
+                ['event_time' => 1200000, 'hard_state' => 2, 'previous_hard_state' => 0],
+                ['event_time' => 1500000, 'hard_state' => 0, 'previous_hard_state' => 2]
+            ],
+            'downtime' => [
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 1100000, 'downtime_end' => 1300000],
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 1400000, 'downtime_end' => 1600000]
+            ],
+        ]);
+
+        // 1000..1100: OK, no downtime
+        // 1100..1200: OK, in downtime
+        // 1200..1300: CRITICAL, in downtime
+        // 1300..1400: CRITICAL, no downtime (only period counting for SLA, -10%)
+        // 1400..1500: CRITICAL, in downtime
+        // 1500..1600: OK, in downtime
+        // 1600..2000: OK, no downtime
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(90.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(90.0, $timeline->getResult());
+    }
+
+    public function testCriticalBeforeInterval()
+    {
+        $this->insertSlaHistoryEvents(
+            ['state' => [['event_time' => 0, 'hard_state' => 2, 'previous_hard_state' => 99]]]
+        );
+
+        // If there is no event within the SLA interval, the last state from before the interval should be used.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(0.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(0.0, $timeline->getResult());
+    }
+
+    public function testCriticalBeforeIntervalWithDowntime()
+    {
+        $this->insertSlaHistoryEvents([
+            'state'    => [['event_time' => 800000, 'hard_state' => 2, 'previous_hard_state' => 99]],
+            'downtime' => [['downtime_id' => $this->makeId(), 'downtime_start' => 600000, 'downtime_end' => 1500000]]
+        ]);
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(50.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(50.0, $timeline->getResult());
+    }
+
+    public function testCriticalBeforeIntervalWithOverlappingDowntimes()
+    {
+        $this->insertSlaHistoryEvents([
+            'state'    => [['event_time' => 800000, 'hard_state' => 2, 'previous_hard_state' => 99]],
+            'downtime' => [
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 600000, 'downtime_end' => 1000000],
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 800000, 'downtime_end' => 1200000],
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 1000000, 'downtime_end' => 1400000],
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 1600000, 'downtime_end' => 2000000],
+                // Everything except 1400-1600 is covered by downtimes, -20%
+                ['downtime_id' => $this->makeId(), 'downtime_start' => 1800000, 'downtime_end' => 2200000]
+            ]
+        ]);
+
+        // Test that overlapping downtimes are properly accounted for.
+        // The period from 1400 to 1600 represents 20% of the total time, and since there was only
+        // one state change 2 (DOWN) before the sla interval, that 20% is a problem time.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(80.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(80.0, $timeline->getResult());
+    }
+
+    public function testFallbackToPreviousState()
+    {
+        $this->insertSlaHistoryEvents(
+            ['state' => [['event_time' => 1100000, 'hard_state' => 0, 'previous_hard_state' => 2]]]
+        );
+
+        // If there is no state event from before the SLA interval, the previous hard state from the first event
+        // after the beginning of the SLA interval should be used as the initial state.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(90.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(90.0, $timeline->getResult());
+    }
+
+    public function testFallbackToCurrentState()
+    {
+        $this->insertObjectCurrentState(2);
+
+        // If there are no state history events, the current state of the checkable should be used.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(0.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(0.0, $timeline->getResult());
+    }
+
+    public function testPreferInitialStateFromBeforeOverLaterState()
+    {
+        $this->insertSlaHistoryEvents([
+            'state' => [
+                ['event_time' => 800000, 'hard_state' => 2, 'previous_hard_state' => 99],
+                ['event_time' => 1600000, 'hard_state' => 0, 'previous_hard_state' => 0],
+            ]
+        ]);
+
+        // The previous_hard_state should only be used as a fallback
+        // when there is no event from before the SLA interval.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(40.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(40.0, $timeline->getResult());
+    }
+
+    public function testPreferInitialStateFromBeforeOverCurrentState()
+    {
+        $this->insertObjectCurrentState(0);
+        $this->insertSlaHistoryEvents(
+            ['state' => [['event_time' => 800000, 'hard_state' => 2, 'previous_hard_state' => 99]]]
+        );
+
+        // The current state should only be used as a fallback when there is no state history event.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(0.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(0.0, $timeline->getResult());
+    }
+
+    public function testPreferLaterStateOverCurrentState()
+    {
+        $this->insertObjectCurrentState(2);
+        $this->insertSlaHistoryEvents(
+            ['state' => [['event_time' => 1300000, 'hard_state' => 0, 'previous_hard_state' => 2]]]
+        );
+
+        // The current state should only be used as a fallback when there is no state history event.
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(70.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(70.0, $timeline->getResult());
+    }
+
+    public function testInitialPendingStateReducesTotalTime()
+    {
+        $this->insertObjectCurrentState(0);
+        $this->insertSlaHistoryEvents([
+            'state' => [
+                ['event_time' => 1600000, 'hard_state' => 2, 'previous_hard_state' => 99],
+                ['event_time' => 1700000, 'hard_state' => 0, 'previous_hard_state' => 2]
+            ]
+        ]);
+
+        // 1000..1600: PENDING (600s)
+        // 1600..1700: DOWN|CRITICAL (100s)
+        // 1700..2000: OK
+        // Total: 2000 - 1000 = 1000
+        // total -= 600s PENDING time = 400
+        // sla = 100 * (total - 100s PROBLEM TIME) / 400 TOTAL = 75%
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(75.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(75.0, $timeline->getResult());
+    }
+
+    public function testIntermediatePendingStateReducesTotalTime()
+    {
+        $this->insertObjectCurrentState(0);
+        $this->insertSlaHistoryEvents([
+            'state' => [
+                ['event_time' => 1000000, 'hard_state' => 0, 'previous_hard_state' => 2],
+                ['event_time' => 1100000, 'hard_state' => 2, 'previous_hard_state' => 0],
+                ['event_time' => 1600000, 'hard_state' => 0, 'previous_hard_state' => 99],
+                ['event_time' => 1800000, 'hard_state' => 2, 'previous_hard_state' => 0]
+            ]
+        ]);
+
+        // 1000..1100: OK|UP
+        // 1100..1600: PENDING (500s)
+        // 1600..1800: OK|UP
+        // 1800..2000: DOWN|CRITICAL (200s PROBLEM TIME)
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'host', $this->hostId);
+        $this->assertSame(60.0, $timeline->getResult());
+
+        $timeline = $this->report->getSlaTimeline($this->start, $this->end, 'service', $this->serviceId);
+        $this->assertSame(60.0, $timeline->getResult());
+    }
+
+    protected function makeId(): string
+    {
+        return random_bytes(20);
+    }
+
+    protected function insertHostAndService()
+    {
+        $this->hostId = $this->makeId();
+        $this->conn->insert('host', [
+            'id'           => $this->hostId,
+            'display_name' => 'icinga2'
+        ]);
+
+        $this->serviceId = $this->makeId();
+        $this->conn->insert('service', [
+            'id'           => $this->serviceId,
+            'host_id'      => $this->hostId,
+            'display_name' => 'disk'
+        ]);
+    }
+
+    protected function insertObjectCurrentState(int $state)
+    {
+        $this->conn->insert('host_state', [
+            'id'         => $this->makeId(),
+            'host_id'    => $this->hostId,
+            'hard_state' => $state
+        ]);
+        $this->conn->insert('service_state', [
+            'id'         => $this->makeId(),
+            'host_id'    => $this->hostId,
+            'service_id' => $this->serviceId,
+            'hard_state' => $state
+        ]);
+    }
+
+    protected function insertSlaHistoryEvents(array $histories)
+    {
+        foreach ($histories as $eventType => $vents) {
+            $table = $eventType === 'state' ? 'sla_history_state' : 'sla_history_downtime';
+            foreach ($vents as $vent) {
+                foreach (['host', 'service'] as $objectType) {
+                    $vent['id'] = $this->makeId();
+                    $vent['host_id'] = $this->hostId;
+                    $vent['object_type'] = $objectType;
+                    if ($objectType === 'service') {
+                        $vent['service_id'] = $this->serviceId;
+                    }
+
+                    $this->conn->insert($table, $vent);
+                }
+            }
+        }
+    }
+}