diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 19bf88f..c5f6b62 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -9,4 +9,4 @@ updates:
     directory: "/"
     schedule:
       # Check for updates to GitHub Actions every weekday
-      interval: "daily"
+      interval: "weekly"
diff --git a/.gitignore b/.gitignore
index f365511..78c231e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 #disable temporary and log files and dirs
 *.log
+/.phpunit.result.cache
 
 #disable composer-managed libraries
 /vendor/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93372e8..b98e1fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### `Security` in case of vulnerabilities
 
+## [2.0.1] - 2024-08-10
+### Added
+- PHPUnit test for class LoggerTime
+
 ## [2.0] - 2024-07-27
 Stable version for `"php": "^7.1 || ^8.0"`. (As of PHP 7.1.0 visibility modifiers are allowed for class constants.)
 
@@ -33,7 +37,8 @@ Stable version for `"php": "^5.3 || ^7.0"`
 ## [0.1] - 2024-07-12
 - A [PSR-3](https://www.php-fig.org/psr/psr-3/) compliant logger with adjustable verbosity (based on Backyard\BackyardError)
 
-[Unreleased]: https://github.com/WorkOfStan/seablast-logger/compare/v2.0...HEAD
+[Unreleased]: https://github.com/WorkOfStan/seablast-logger/compare/v2.0.1...HEAD
+[2.0.1]: https://github.com/WorkOfStan/seablast-logger/compare/v2.0...v2.0.1
 [2.0]: https://github.com/WorkOfStan/seablast-logger/compare/v1.0...v2.0
 [1.0]: https://github.com/WorkOfStan/seablast-logger/compare/v0.2...v1.0
 [0.2]: https://github.com/WorkOfStan/seablast-logger/compare/v0.1...v0.2
diff --git a/Test/LoggerTimeTest.php b/Test/LoggerTimeTest.php
new file mode 100644
index 0000000..4cb9cd7
--- /dev/null
+++ b/Test/LoggerTimeTest.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace Seablast\Logger\Test;
+
+use PHPUnit\Framework\TestCase;
+use Seablast\Logger\LoggerTime;
+
+/**
+ * Generated by PHPUnit_SkeletonGenerator on 2016-06-25 at 17:57:37.
+ */
+class LoggerTimeTest extends TestCase
+{
+    /** @var LoggerTime */
+    protected $object;
+
+    /**
+     * Sets up the fixture, for example, opens a network connection.
+     * This method is called before a test is executed.
+     *
+     * @return void
+     */
+    protected function setUp(): void
+    {
+        error_reporting(E_ALL); // incl E_NOTICE
+        $this->object = new LoggerTime();
+    }
+
+    /**
+     * Tears down the fixture, for example, closes a network connection.
+     * This method is called after a test is executed.
+     *
+     * @return void
+     */
+    protected function tearDown(): void
+    {
+        // no action
+    }
+
+    /**
+     * @covers Seablast\Logger\LoggerTime::getmicrotime
+     *
+     * @return void
+     */
+    public function testGetmicrotime(): void
+    {
+        $this->assertTrue(is_float($this->object->getmicrotime()));
+    }
+
+    /**
+     * @covers Seablast\Logger\LoggerTime::getRunningTime
+     *
+     * @return void
+     */
+    public function testGetRunningTime(): void
+    {
+        $expected = '0.0';
+
+        //$this->assertEquals($expected, substr((string) $this->object->getRunningTime(), 0, 3));
+        $this->assertEquals((float) $expected, (float) substr((string) $this->object->getRunningTime(), 0, 3));
+    }
+
+    /**
+     * @covers Seablast\Logger\LoggerTime::pageGeneratedIn
+     *
+     * @return void
+     */
+    public function testPageGeneratedInDefault(): void
+    {
+        $expected = '0.0';
+
+        //$this->assertEquals($expected, substr($this->object->pageGeneratedIn(), 0, 3));
+        $this->assertEquals((float) $expected, (float) substr((string) $this->object->pageGeneratedIn(), 0, 3));
+    }
+
+    /**
+     * @return void
+     */
+    public function testPageGeneratedInLangString(): void
+    {
+        $langStringPageGeneratedIn = "Page Generated in %s";
+        $expected = 'Page Generated in 0';
+
+        $this->assertEquals(
+            $expected,
+            substr($this->object->pageGeneratedIn($langStringPageGeneratedIn), 0, strlen($expected))
+        );
+    }
+}
diff --git a/composer.json b/composer.json
index 24eeb3a..6a011f4 100644
--- a/composer.json
+++ b/composer.json
@@ -7,6 +7,9 @@
         "psr/log": "^1.0 || ^2.0 || ^3.0",
         "tracy/tracy": "^2.6.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^6 || ^7 || ^8 || ^9 || ^10 || ^11"
+    },
     "license": "MIT",
     "authors": [
         {
@@ -28,5 +31,10 @@
         "psr-4": {
             "Seablast\\Logger\\": ["src/"]
         }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Seablast\\Logger\\Test\\": ["Test/"]
+        }
     }
 }
diff --git a/conf/phpunit-github.xml b/conf/phpunit-github.xml
new file mode 100644
index 0000000..80d653f
--- /dev/null
+++ b/conf/phpunit-github.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit 
+    colors="true"
+    stderr="true"
+    convertErrorsToExceptions="true"
+    convertNoticesToExceptions="true"
+    convertWarningsToExceptions="true"
+    stopOnFailure="false"> 
+    <testsuites> 
+        <testsuite name="Application Test Suite"> 
+            <directory>./../Test/</directory> 
+        </testsuite> 
+    </testsuites> 
+</phpunit>
\ No newline at end of file
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..317a24c
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+    colors="true"
+    stderr="true"
+    convertErrorsToExceptions="true"
+    convertNoticesToExceptions="true"
+    convertWarningsToExceptions="true"
+    stopOnFailure="false">
+    <testsuites>
+        <testsuite name="Application Test Suite">
+            <directory>./Test/</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>
diff --git a/src/ErrorLogFailureException.php b/src/ErrorLogFailureException.php
index 46fcb2e..784788e 100644
--- a/src/ErrorLogFailureException.php
+++ b/src/ErrorLogFailureException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Seablast\Logger;
 
 class ErrorLogFailureException extends \Exception
diff --git a/src/Logger.php b/src/Logger.php
index b76bfc2..cb915bc 100644
--- a/src/Logger.php
+++ b/src/Logger.php
@@ -1,14 +1,17 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Seablast\Logger;
 
 use Psr\Log\AbstractLogger;
 use Psr\Log\LoggerInterface;
 use Psr\Log\LogLevel;
-use Seablast\Logger\LoggerTime;
 
 /**
  * A [PSR-3](http://www.php-fig.org/psr/psr-3/) compliant logger with adjustable verbosity.
+ *
+ * Note: Until PHP 7.3, the parameter #1 $message in methods implementing `Psr\Log\AbstractLogger` is of type `mixed`.
  */
 class Logger extends AbstractLogger implements LoggerInterface
 {
@@ -23,7 +26,7 @@ class Logger extends AbstractLogger implements LoggerInterface
     public const CONF_MAIL_FOR_ADMIN_ENABLED = 'mail_for_admin_enabled';
 
     /** @var array<mixed> int,string,bool,array */
-    protected $conf = array();
+    protected $conf = [];
     /** @var int */
     private $overrideLoggingLevel;
     /** @var float */
@@ -34,15 +37,14 @@ class Logger extends AbstractLogger implements LoggerInterface
     private $user = 'unidentified';
 
     /**
-     *
      * @param array<mixed> $conf
-     * @param LoggerTime $time
+     * @param ?LoggerTime $time
      */
-    public function __construct(array $conf = array(), LoggerTime $time = null)
+    public function __construct(array $conf = [], ?LoggerTime $time = null)
     {
         $this->time = ($time === null) ? (new LoggerTime()) : $time;
         $this->conf = array_merge(
-            array( // default values
+            [ // default values
                 // 0 = send message to PHP's system logger;
                 // recommended is however 3, i.e. append to the file destination set in the field 'logging_file'
                 self::CONF_ERROR_LOG_MESSAGE_TYPE => 0,
@@ -51,15 +53,15 @@ public function __construct(array $conf = array(), LoggerTime $time = null)
                 // verbosity: log up to the level set here, default=5 = debug
                 self::CONF_LOGGING_LEVEL => 5,
                 // rename or renumber, if needed
-                self::CONF_LOGGING_LEVEL_NAME => array(
+                self::CONF_LOGGING_LEVEL_NAME => [
                     0 => 'unknown',
                     1 => 'fatal',
                     'error',
                     'warning',
                     'info',
                     'debug',
-                    'speed'
-                ),
+                    'speed',
+                ],
                 // the logging level to which the page generation speed (i.e. error_number 6) is to be logged
                 self::CONF_LOGGING_LEVEL_PAGE_SPEED => 5,
                 // false => use logging_file with log extension as destination
@@ -70,7 +72,7 @@ public function __construct(array $conf = array(), LoggerTime $time = null)
                 // A fatal error may be logged only.
                 // However, in production, set up an email address to enable error notifications.
                 self::CONF_MAIL_FOR_ADMIN_ENABLED => false,
-            ),
+            ],
             $conf
         );
         if (!is_int($this->conf[self::CONF_LOGGING_LEVEL])) {
@@ -86,6 +88,7 @@ public function __construct(array $conf = array(), LoggerTime $time = null)
      * It is however possible to programmatically raise the logging level set in configuration.
      *
      * @param int $newLevel
+     *
      * @return void
      */
     public function logAtLeastToLevel(int $newLevel): void
@@ -108,6 +111,7 @@ public function getLastRunningTime(): float
      * DI setter.
      *
      * @param int|string $user
+     *
      * @return void
      */
     public function setUser($user): void
@@ -120,9 +124,10 @@ public function setUser($user): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function emergency($message, array $context = array()): void
+    public function emergency($message, array $context = []): void
     {
         $this->log(0, $message, $context);
     }
@@ -135,9 +140,10 @@ public function emergency($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function alert($message, array $context = array()): void
+    public function alert($message, array $context = []): void
     {
         $this->log(1, $message, $context);
     }
@@ -149,9 +155,10 @@ public function alert($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function critical($message, array $context = array()): void
+    public function critical($message, array $context = []): void
     {
         $this->log(1, $message, $context);
     }
@@ -162,9 +169,10 @@ public function critical($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function error($message, array $context = array()): void
+    public function error($message, array $context = []): void
     {
         $this->log(2, $message, $context);
     }
@@ -177,9 +185,10 @@ public function error($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function warning($message, array $context = array()): void
+    public function warning($message, array $context = []): void
     {
         $this->log(3, $message, $context);
     }
@@ -189,9 +198,10 @@ public function warning($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function notice($message, array $context = array()): void
+    public function notice($message, array $context = []): void
     {
         $this->log(4, $message, $context);
     }
@@ -203,9 +213,10 @@ public function notice($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function info($message, array $context = array()): void
+    public function info($message, array $context = []): void
     {
         $this->log(4, $message, $context);
     }
@@ -215,9 +226,10 @@ public function info($message, array $context = array()): void
      *
      * @param string $message
      * @param array<int> $context
+     *
      * @return void
      */
-    public function debug($message, array $context = array()): void
+    public function debug($message, array $context = []): void
     {
         $this->log(5, $message, $context);
     }
@@ -259,28 +271,27 @@ public function debug($message, array $context = array()): void
      *  23 Algorithm flow<br/>
      *  24 Third party API<br/>
      *  1001 Establish correct error_number
-     *
      */
-    public function log($level, $message, array $context = array()): void
+    public function log($level, $message, array $context = []): void
     {
         //TODO add variable $line - it should always be called as basename(__FILE__)."#".__LINE__ ,
         //so it's clear which line of the source code triggered the call
         if (!is_string($message)) {
-            $message = "wrong message type " . gettype($message) . ": Logger->log(" . print_r($level, true) . ","
-                . print_r($message, true) . ")";
+            $message = 'wrong message type ' . gettype($message) . ': Logger->log(' . print_r($level, true) . ','
+                . print_r($message, true) . ')';
             $this->error($message);
         }
         // psr log levels to numbered severity
-        $psr2int = array(
+        $psr2int = [
             LogLevel::EMERGENCY => 0,
-            LogLevel::ALERT     => 1,
-            LogLevel::CRITICAL  => 1,
-            LogLevel::ERROR     => 2,
-            LogLevel::WARNING   => 3,
-            LogLevel::NOTICE    => 4,
-            LogLevel::INFO      => 4,
-            LogLevel::DEBUG     => 5,
-        );
+            LogLevel::ALERT => 1,
+            LogLevel::CRITICAL => 1,
+            LogLevel::ERROR => 2,
+            LogLevel::WARNING => 3,
+            LogLevel::NOTICE => 4,
+            LogLevel::INFO => 4,
+            LogLevel::DEBUG => 5,
+        ];
         if (is_string($level)) {
             if (array_key_exists($level, $psr2int)) {
                 $level = $psr2int[$level];
@@ -294,7 +305,7 @@ public function log($level, $message, array $context = array()): void
         }
 
         // if context array is set then get the value of the 'error_number' field or the first element
-        $error_number = ($context === array())
+        $error_number = ($context === [])
             ? 0
             : (isset($context['error_number']) ? (int) $context['error_number'] : (int) reset($context));
 
@@ -304,10 +315,10 @@ public function log($level, $message, array $context = array()): void
             // log 0=unknown/default 1=fatal 2=error 3=warning 4=info 5=debug 6=speed according to $level
             (
                 $level <= max(
-                    array(
+                    [
                         $this->conf[self::CONF_LOGGING_LEVEL],
                         $this->overrideLoggingLevel,
-                    )
+                    ]
                 )
             )
             // or log page_speed everytime error_number equals 6 and
@@ -324,31 +335,31 @@ public function log($level, $message, array $context = array()): void
                     - $RUNNING_TIME_PREVIOUS) > $this->conf[self::CONF_LOG_PROFILING_STEP]
                 ) && $this->conf[self::CONF_LOG_PROFILING_STEP]
             ) {
-                $message = "SLOWSTEP " . $message; //110812, PROFILING
+                $message = 'SLOWSTEP ' . $message; //110812, PROFILING
             }
 
-            $message_prefix = "[" . date("d-M-Y H:i:s") . "] [" . $this->conf[self::CONF_LOGGING_LEVEL_NAME][$level]
-                . "] [" . $error_number . "] [" . $_SERVER['SCRIPT_FILENAME'] . "] ["
-                . $this->user . "@"
+            $message_prefix = '[' . date('d-M-Y H:i:s') . '] [' . $this->conf[self::CONF_LOGGING_LEVEL_NAME][$level]
+                . '] [' . $error_number . '] [' . $_SERVER['SCRIPT_FILENAME'] . '] ['
+                . $this->user . '@'
                 // PHPUnit test (CLI) does not set REMOTE_ADDR
                 // TODO what if gethostbyaddr can't resolve the IP? And wouldn't be faster to log IP?
                 . (isset($_SERVER['REMOTE_ADDR']) ? gethostbyaddr($_SERVER['REMOTE_ADDR']) : '-')
-                . "] [" . $this->runningTime . "] ["
+                . '] [' . $this->runningTime . '] ['
                 // PHPUnit test (CLI) does not set REQUEST_URI
-                . (isset($_SERVER["REQUEST_URI"]) ? $_SERVER["REQUEST_URI"] : '-')
-                . "] ";
+                . (isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '-')
+                . '] ';
             // $logging_file not set and it should be
             if (($this->conf[self::CONF_ERROR_LOG_MESSAGE_TYPE] == 3) && !$this->conf[self::CONF_LOGGING_FILE]) {
                 // so write into the default destination
-                $result = error_log($message_prefix . "(error: logging_file should be set!) $message");
+                $result = error_log("{$message_prefix}(error: logging_file should be set!) {$message}");
             } else {
-                $messageType = ($this->conf[self::CONF_ERROR_LOG_MESSAGE_TYPE] == 0)
+                $messageType = ($this->conf[self::CONF_ERROR_LOG_MESSAGE_TYPE] === 0)
                     ? $this->conf[self::CONF_ERROR_LOG_MESSAGE_TYPE] : 3;
-                $result = ($this->conf[self::CONF_LOG_MONTHLY_ROTATION])
+                $result = $this->conf[self::CONF_LOG_MONTHLY_ROTATION]
                     ? error_log(
-                        $message_prefix . $message . (($messageType != 0) ? (PHP_EOL) : ('')),
+                        $message_prefix . $message . (($messageType != 0) ? PHP_EOL : ''),
                         $messageType,
-                        "{$this->conf[self::CONF_LOGGING_FILE]}." . date("Y-m") . ".log"
+                        "{$this->conf[self::CONF_LOGGING_FILE]}." . date('Y-m') . '.log'
                     ) // writes into a monthly rotating file
                     : error_log(
                         $message_prefix . $message . PHP_EOL,
@@ -357,7 +368,7 @@ public function log($level, $message, array $context = array()): void
                     ); // writes into one file
             }
             // mailto admin. 'mail_for_admin_enabled' has to be an email
-            if ($level == 1 && $this->conf[self::CONF_MAIL_FOR_ADMIN_ENABLED]) {
+            if ($level === 1 && $this->conf[self::CONF_MAIL_FOR_ADMIN_ENABLED]) {
                 error_log($message_prefix . $message . PHP_EOL, 1, $this->conf[self::CONF_MAIL_FOR_ADMIN_ENABLED]);
             }
         }
diff --git a/src/LoggerTime.php b/src/LoggerTime.php
index 23bd221..ad3a888 100644
--- a/src/LoggerTime.php
+++ b/src/LoggerTime.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Seablast\Logger;
 
 class LoggerTime
@@ -19,20 +21,19 @@ public function __construct()
      *
      * @return float
      */
-    public function getmicrotime()
+    public function getmicrotime(): float
     {
         if (version_compare((string) phpversion(), '5.0.0') == -1) {
             list($usec, $sec) = explode(' ', microtime());
-            return ((float) $usec + (float) $sec);
+            return (float) $usec + (float) $sec;
         }
         return microtime(true);
     }
 
     /**
-     *
      * @return float
      */
-    public function getPageTimestamp()
+    public function getPageTimestamp(): float
     {
         if (is_null($this->pageTimestamp)) {
             $this->pageTimestamp = $this->getmicrotime(); // initialisation, so that it can't return null
@@ -45,7 +46,7 @@ public function getPageTimestamp()
      *
      * @return float
      */
-    public function getRunningTime()
+    public function getRunningTime(): float
     {
         return round($this->getmicrotime() - $this->pageTimestamp, 4);
     }
@@ -54,9 +55,10 @@ public function getRunningTime()
      * If called with 'Page Generated in %s seconds', it returns "Page Generated in x.xxxx seconds"
      *
      * @param string $langStringPageGeneratedIn instead of $backyardLangString['page_generated_in']
+     *
      * @return string
      */
-    public function pageGeneratedIn($langStringPageGeneratedIn = '%s')
+    public function pageGeneratedIn(string $langStringPageGeneratedIn = '%s'): string
     {
         return str_replace(
             '%s',
diff --git a/test.php b/test.php
index 61880cf..06143de 100644
--- a/test.php
+++ b/test.php
@@ -1,11 +1,13 @@
 <?php
 
+declare(strict_types=1);
+
 use Seablast\Logger\Logger;
 
 require 'vendor/autoload.php';
 
 // Initialize the logger
-$conf = array(
+$conf = [
     Logger::CONF_ERROR_LOG_MESSAGE_TYPE => 3,
     Logger::CONF_LOGGING_FILE => './error_log', // extension .log will be added automatically
     Logger::CONF_LOGGING_LEVEL => 0, // start with logging almost nothing for purpose of test looping
@@ -13,14 +15,14 @@
     Logger::CONF_LOG_MONTHLY_ROTATION => true,
     Logger::CONF_LOG_PROFILING_STEP => 0.00048,
     Logger::CONF_MAIL_FOR_ADMIN_ENABLED => false,
-);
+];
 $logger = new Logger($conf);
 
-$severities = array('emergency', 'alert', 'critical', 'error', 'warning', 'notice', 'info', 'debug');
+$severities = ['emergency', 'alert', 'critical', 'error', 'warning', 'notice', 'info', 'debug'];
 // Loop through levels 1 to 5
 for ($level = 1; $level <= 5; $level++) {
     // Set the logging level
-    echo "<h1>logAtLeastToLevel($level)</h1>";
+    echo "<h1>logAtLeastToLevel({$level})</h1>";
     $logger->logAtLeastToLevel($level);
 
     foreach ($severities as $severity) {