diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 2ce6d09..8b4c862 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -14,8 +14,8 @@ jobs:
     strategy:
       matrix:
         php-version:
-          - 7.3
           - 7.4
+          - 8.0
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -28,16 +28,23 @@ jobs:
       - name: PHP lint
         run: "find *.php Classes Configuration Tests -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l"
 
-  check-dependencies:
+  check-dependencies-TYPO3-v10:
     runs-on: ubuntu-latest
-    needs: [check-composer]
+    needs:
+      - check-composer
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+        typo3-version:
+          - '^10.4'
     steps:
       - uses: actions/checkout@v2
 
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: "7.3"
+          php-version: "${{ matrix.php-version }}"
 
       - name: Get Composer Cache Directory
         id: composer-cache
@@ -51,25 +58,66 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
-
       - name: Install dependencies
-        run: composer install --prefer-dist --no-progress --no-suggest --no-plugins
+        run: composer install --prefer-dist --no-progress --no-plugins
+
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --no-plugins --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
 
       - name: Missing composer requirements
         run: ./vendor/bin/composer-require-checker check --config-file dependency-checker.json
 
-  xml-linting:
+  check-dependencies-TYPO3-v11:
     runs-on: ubuntu-latest
-    needs: [check-composer]
+    needs:
+      - check-composer
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+          - '8.0'
+        typo3-version:
+          - '11.2.*'
     steps:
       - uses: actions/checkout@v2
 
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: "7.3"
+          php-version: "${{ matrix.php-version }}"
+
+      - name: Get Composer Cache Directory
+        id: composer-cache
+        run: |
+            echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-plugins
+
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --no-plugins --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
+      - name: Missing composer requirements
+        run: ./vendor/bin/composer-require-checker check --config-file dependency-checker.json
+
+  xml-linting:
+    runs-on: ubuntu-latest
+    needs:
+      - check-composer
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "7.4"
 
       - name: Install xmllint
         run: sudo apt-get install libxml2-utils
@@ -86,9 +134,6 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
-
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -106,8 +151,7 @@ jobs:
 
   coding-guideline:
     runs-on: ubuntu-latest
-    needs: 
-      - check-dependencies
+    needs:
       - xml-linting
     steps:
       - uses: actions/checkout@v2
@@ -115,7 +159,7 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: "7.3"
+          php-version: "7.4"
 
       - name: Get Composer Cache Directory
         id: composer-cache
@@ -129,25 +173,23 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
-
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
       - name: Coding Guideline
         run: ./vendor/bin/phpcs
 
-  tests-sqlite:
+  tests-sqlite-TYPO3-v10:
     runs-on: ubuntu-latest
     needs:
-      - check-dependencies
+      - check-dependencies-TYPO3-v10
       - xml-linting
     strategy:
       matrix:
         php-version:
-          - 7.3
-          - 7.4
+          - '7.4'
+        typo3-version:
+          - '^10.4'
     steps:
       - uses: actions/checkout@v2
 
@@ -168,25 +210,67 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
-
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
       - name: PHPUnit Tests
         run: ./vendor/bin/phpunit --testdox
 
-  tests-mysql:
+  tests-sqlite-TYPO3-v11:
     runs-on: ubuntu-latest
     needs:
-      - check-dependencies
+      - check-dependencies-TYPO3-v11
       - xml-linting
     strategy:
       matrix:
         php-version:
-          - 7.3
-          - 7.4
+          - '7.4'
+          - '8.0'
+        typo3-version:
+          - '11.2.*'
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "${{ matrix.php-version }}"
+
+      - name: Get Composer Cache Directory
+        id: composer-cache
+        run: |
+            echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
+      - name: PHPUnit Tests
+        run: ./vendor/bin/phpunit --testdox
+
+  tests-mysql-TYPO3-v10:
+    runs-on: ubuntu-latest
+    needs:
+      - check-dependencies-TYPO3-v10
+      - xml-linting
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+        typo3-version:
+          - '^10.4'
     steps:
       - uses: actions/checkout@v2
 
@@ -210,12 +294,12 @@ jobs:
       - name: Start MySQL
         run: sudo /etc/init.d/mysql start
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
-
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
       - name: PHPUnit Tests
         run: |-
           export typo3DatabaseDriver="mysqli"
@@ -225,16 +309,25 @@ jobs:
           export typo3DatabasePassword="root"
           ./vendor/bin/phpunit --testdox
 
-  code-quality:
+  tests-mysql-TYPO3-v11:
     runs-on: ubuntu-latest
-    needs: [check-dependencies]
+    needs:
+      - check-dependencies-TYPO3-V11
+      - xml-linting
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+          - '8.0'
+        typo3-version:
+          - '11.2.*'
     steps:
       - uses: actions/checkout@v2
 
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: "7.3"
+          php-version: "${{ matrix.php-version }}"
 
       - name: Get Composer Cache Directory
         id: composer-cache
@@ -248,11 +341,99 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
-      - name: Keep composer V1 until all dev dependencies are ready
-        run: sudo composer selfupdate --1
+      - name: Start MySQL
+        run: sudo /etc/init.d/mysql start
 
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
+      - name: PHPUnit Tests
+        run: |-
+          export typo3DatabaseDriver="mysqli"
+          export typo3DatabaseName="typo3"
+          export typo3DatabaseHost="127.0.0.1"
+          export typo3DatabaseUsername="root"
+          export typo3DatabasePassword="root"
+          ./vendor/bin/phpunit --testdox
+
+  code-quality-TYPO3-v10:
+    runs-on: ubuntu-latest
+    needs:
+      - check-dependencies-TYPO3-v10
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+        typo3-version:
+          - '^10.4'
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "${{ matrix.php-version }}"
+
+      - name: Get Composer Cache Directory
+        id: composer-cache
+        run: |
+            echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
+      - name: Code Quality (by PHPStan)
+        run: ./vendor/bin/phpstan analyse
+
+  code-quality-TYPO3-v11:
+    runs-on: ubuntu-latest
+    needs:
+      - check-dependencies-TYPO3-v11
+    strategy:
+      matrix:
+        php-version:
+          - '7.4'
+          - '8.0'
+        typo3-version:
+          - '11.2.*'
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "${{ matrix.php-version }}"
+
+      - name: Get Composer Cache Directory
+        id: composer-cache
+        run: |
+            echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Switch to expected TYPO3 Version
+        run: composer require --prefer-dist --no-progress --update-with-all-dependencies "typo3/cms-backend:${{ matrix.typo3-version }}" "typo3/cms-core:${{ matrix.typo3-version }}" "typo3/cms-dashboard:${{ matrix.typo3-version }}"
+
       - name: Code Quality (by PHPStan)
         run: ./vendor/bin/phpstan analyse
diff --git a/Classes/Dashboard/Provider/PageviewsPerDay.php b/Classes/Dashboard/Provider/PageviewsPerDay.php
index 28bbb5d..3c88edc 100644
--- a/Classes/Dashboard/Provider/PageviewsPerDay.php
+++ b/Classes/Dashboard/Provider/PageviewsPerDay.php
@@ -101,9 +101,9 @@ class PageviewsPerDay implements ChartDataProviderInterface
         $data = [];
 
         for ($daysBefore = $this->days; $daysBefore >= 0; $daysBefore--) {
-            $timeForLabel = strtotime('-' . $daysBefore . ' day');
-            $startPeriod = strtotime('-' . $daysBefore . ' day 0:00:00');
-            $endPeriod =  strtotime('-' . $daysBefore . ' day 23:59:59');
+            $timeForLabel = (int) strtotime('-' . $daysBefore . ' day');
+            $startPeriod = (int) strtotime('-' . $daysBefore . ' day 0:00:00');
+            $endPeriod =  (int) strtotime('-' . $daysBefore . ' day 23:59:59');
 
             $labels[] = date($this->dateFormat, $timeForLabel);
             $data[] = $this->getPageviewsInPeriod($startPeriod, $endPeriod);
diff --git a/composer.json b/composer.json
index e864d1a..b7b5671 100644
--- a/composer.json
+++ b/composer.json
@@ -26,25 +26,25 @@
         }
     },
     "require": {
-        "doctrine/dbal": "^2.10",
+        "doctrine/dbal": "^2.12",
         "ext-mbstring": "*",
-        "php": "^7.3.0",
+        "php": "~7.4.0 || ~8.0.0",
         "psr/http-message": "^1.0",
         "psr/http-server-handler": "^1.0",
         "psr/http-server-middleware": "^1.0",
-        "symfony/console": "^4.0 || ^5.0",
-        "symfony/expression-language": "^4.0 || ^5.0",
-        "typo3/cms-backend": "^10.4",
-        "typo3/cms-core": "^10.4",
-        "typo3/cms-dashboard": "^10.4"
+        "symfony/console": "^5.2",
+        "symfony/expression-language": "^5.2",
+        "typo3/cms-backend": "^10.4 || ~11.2",
+        "typo3/cms-core": "^10.4 || ~11.2",
+        "typo3/cms-dashboard": "^10.4 || ~11.2"
     },
     "require-dev": {
         "squizlabs/php_codesniffer": "^3.5",
         "phpunit/phpunit": "^9.0",
         "phpstan/phpstan": "^0.12.18",
         "phpstan/extension-installer": "^1.0",
-        "jangregor/phpstan-prophecy": "^0.6.2",
-        "maglnet/composer-require-checker": "^2.1",
+        "jangregor/phpstan-prophecy": "^0.8.1",
+        "maglnet/composer-require-checker": "^3.2",
         "phpspec/prophecy-phpunit": "^2.0",
         "typo3/testing-framework": "^6.3",
         "saschaegerer/phpstan-typo3": "^0.13.1"
diff --git a/phpstan.neon b/phpstan.neon
index 22b9fa5..71d805d 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -9,15 +9,3 @@ parameters:
         - '#Cannot call method fetch\(\) on Doctrine\\DBAL\\Driver\\Statement\|int\.#'
         - '#Cannot call method fetchAll\(\) on Doctrine\\DBAL\\Driver\\Statement\|int\.#'
         - '#Cannot call method fetchColumn\(\) on Doctrine\\DBAL\\Driver\\Statement\|int\.#'
-        -
-            message: '#\$timestamp of function date expects int, int\|false given\.#'
-            path: Classes/Dashboard/Provider/PageviewsPerDay.php
-            count: 1
-        -
-            message: '#Parameter \#1 \$start of method DanielSiepmann\\Tracking\\Dashboard\\Provider\\PageviewsPerDay::getPageviewsInPeriod\(\) expects int, int\|false given\.#'
-            path: Classes/Dashboard/Provider/PageviewsPerDay.php
-            count: 1
-        -
-            message: '#Parameter \#2 \$end of method DanielSiepmann\\Tracking\\Dashboard\\Provider\\PageviewsPerDay::getPageviewsInPeriod\(\) expects int, int\|false given\.#'
-            path: Classes/Dashboard/Provider/PageviewsPerDay.php
-            count: 1