diff --git a/.gitignore b/.gitignore
index 5b647aa1..de11480f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ coverage
 sandbox
 phpmd.html
 phpdoc.xml
+.phpunit.result.cache
 
 # User plugin configuration
 plugins/*
diff --git a/application/Utils.php b/application/Utils.php
index c5cd884b..073004cf 100644
--- a/application/Utils.php
+++ b/application/Utils.php
@@ -197,7 +197,7 @@ function generateLocation($referer, $host, $loopTerms = [])
 function autoLocale($headerLocale)
 {
     // Default if browser does not send HTTP_ACCEPT_LANGUAGE
-    $locales = ['en_US', 'en_US.utf8', 'en_US.UTF-8'];
+    $locales = ['en_US.UTF-8', 'en_US.utf8', 'en_US'];
     if (! empty($headerLocale)) {
         if (preg_match_all('/([a-z]{2,3})[-_]?([a-z]{2})?,?/i', $headerLocale, $matches, PREG_SET_ORDER)) {
             $attempts = [];
@@ -314,10 +314,12 @@ function format_date($date, $time = true, $intl = true)
     }
 
     if (! $intl || ! class_exists('IntlDateFormatter')) {
-        $format = $time ? '%c' : '%x';
-        return strftime($format, $date->getTimestamp());
+        $format = 'F j, Y';
+        if ($time) {
+            $format .= ' h:i:s A \G\M\TP';
+        }
+        return $date->format($format);
     }
-
     $formatter = new IntlDateFormatter(
         setlocale(LC_TIME, 0),
         IntlDateFormatter::LONG,
diff --git a/application/helper/DailyPageHelper.php b/application/helper/DailyPageHelper.php
index 05f95812..cb4494a8 100644
--- a/application/helper/DailyPageHelper.php
+++ b/application/helper/DailyPageHelper.php
@@ -60,6 +60,11 @@ class DailyPageHelper
             ;
         }
 
+        // Don't use today's day of month (github issue #1844)
+        if ($type === static::MONTH) {
+            $format = '!' . $format;
+        }
+
         // W is not supported by createFromFormat...
         if ($type === static::WEEK) {
             return (new DateTimeImmutable())
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 9d05b3d5..e0403296 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -30,9 +30,13 @@ require_once 'tests/TestCase.php';
 require_once 'tests/container/ShaarliTestContainer.php';
 require_once 'tests/front/controller/visitor/FrontControllerMockHelper.php';
 require_once 'tests/front/controller/admin/FrontAdminControllerMockHelper.php';
+require_once 'tests/updater/DummyUpdater.php';
+require_once 'tests/utils/FakeApplicationUtils.php';
+require_once 'tests/utils/FakeBookmarkService.php';
 require_once 'tests/utils/FakeConfigManager.php';
 require_once 'tests/utils/ReferenceHistory.php';
 require_once 'tests/utils/ReferenceLinkDB.php';
+require_once 'tests/utils/ReferenceSessionIdHashes.php';
 
 ReferenceSessionIdHashes::genAllHashes();
 
diff --git a/tests/front/controller/visitor/DailyControllerTest.php b/tests/front/controller/visitor/DailyControllerTest.php
index b6574b6c..a0dd54e1 100644
--- a/tests/front/controller/visitor/DailyControllerTest.php
+++ b/tests/front/controller/visitor/DailyControllerTest.php
@@ -667,11 +667,11 @@ class DailyControllerTest extends TestCase
     public function testSimpleRssMonthly(): void
     {
         $dates = [
-            new \DateTimeImmutable('2020-05-19'),
+            new \DateTimeImmutable('2022-02-19'),
             new \DateTimeImmutable('2020-04-13'),
         ];
         $expectedDates = [
-            new \DateTimeImmutable('2020-05-31 23:59:59'),
+            new \DateTimeImmutable('2022-02-28 23:59:59'),
             new \DateTimeImmutable('2020-04-30 23:59:59'),
         ];
 
@@ -710,7 +710,7 @@ class DailyControllerTest extends TestCase
 
         static::assertEquals($date, $day['date']);
         static::assertSame($date->format(\DateTime::RSS), $day['date_rss']);
-        static::assertSame('May, 2020', $day['date_human']);
+        static::assertSame('February, 2022', $day['date_human']);
         static::assertSame('http://shaarli/subfolder/daily?month=' . $dates[0]->format('Ym'), $day['absolute_url']);
         static::assertCount(1, $day['links']);
 
diff --git a/tests/helper/DailyPageHelperTest.php b/tests/helper/DailyPageHelperTest.php
index 4a4b95b2..8dab908d 100644
--- a/tests/helper/DailyPageHelperTest.php
+++ b/tests/helper/DailyPageHelperTest.php
@@ -258,7 +258,7 @@ class DailyPageHelperTest extends TestCase
         return [
             [DailyPageHelper::DAY, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-09 00:00:00')],
             [DailyPageHelper::WEEK, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-05 00:00:00')],
-            [DailyPageHelper::MONTH, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-01 00:00:00')],
+            [DailyPageHelper::MONTH, new DateTimeImmutable('2022-03-30 04:05:06'), new DateTime('2022-03-01 00:00:00')],
         ];
     }
 
@@ -270,7 +270,8 @@ class DailyPageHelperTest extends TestCase
         return [
             [DailyPageHelper::DAY, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-09 23:59:59')],
             [DailyPageHelper::WEEK, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-11 23:59:59')],
-            [DailyPageHelper::MONTH, new DateTimeImmutable('2020-10-09 04:05:06'), new DateTime('2020-10-31 23:59:59')],
+            [DailyPageHelper::MONTH, new DateTimeImmutable('2022-02-28 04:05:06'), new DateTime('2022-02-28 23:59:59')],
+            [DailyPageHelper::MONTH, new DateTimeImmutable('2022-03-30 04:05:06'), new DateTime('2022-03-31 23:59:59')],
         ];
     }
 
diff --git a/tests/languages/de/UtilsDeTest.php b/tests/languages/de/UtilsDeTest.php
index 9713009d..d7a16eac 100644
--- a/tests/languages/de/UtilsDeTest.php
+++ b/tests/languages/de/UtilsDeTest.php
@@ -6,13 +6,25 @@ use DateTime;
 
 class UtilsDeTest extends UtilsTest
 {
+    /**
+     * Test for international date formatter class. Other tests
+     * will fail without it!
+     */
+    public function testIntlDateFormatter()
+    {
+        $this->assertTrue(class_exists('IntlDateFormatter'));
+    }
+
     /**
      * Test date_format().
      */
     public function testDateFormat()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/1\. Januar 2017 (um )?10:11:12 GMT\+0?3(:00)?/', format_date($date, true, true));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('de-de');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/2\. Januar 2017 (um )?20:11:12 GMT\+0?3(:00)?/', format_date($date, true, true));
+        setlocale(LC_ALL, $current);
     }
 
     /**
@@ -20,26 +32,29 @@ class UtilsDeTest extends UtilsTest
      */
     public function testDateFormatNoTime()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/1\. Januar 2017/', format_date($date, false, true));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('de-de');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/2\. Januar 2017/', format_date($date, false, true));
+        setlocale(LC_ALL, $current);
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefault()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertEquals('So 01 Jan 2017 10:11:12 EAT', format_date($date, true, false));
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_101112');
+        $this->assertEquals('January 2, 2017 10:11:12 AM GMT+03:00', format_date($date, true, false));
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime without time.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefaultNoTime()
     {
         $date = DateTime::createFromFormat('Ymd_His', '20170201_101112');
-        $this->assertEquals('01.02.2017', format_date($date, false, false));
+        $this->assertEquals('February 1, 2017', format_date($date, false, false));
     }
 
     /**
@@ -61,7 +76,7 @@ class UtilsDeTest extends UtilsTest
     public function testAutoLocaleValidAlternative()
     {
         $current = setlocale(LC_ALL, 0);
-        $header = 'en_us.UTF8';
+        $header = 'en_US.UTF-8';
         autoLocale($header);
         $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
 
@@ -87,7 +102,7 @@ class UtilsDeTest extends UtilsTest
     public function testAutoLocaleMultipleSecondAvailable()
     {
         $current = setlocale(LC_ALL, 0);
-        $header = 'mag_IN,fr-fr';
+        $header = 'mgg_IN,fr-fr';
         autoLocale($header);
         $this->assertEquals('fr_FR.utf8', setlocale(LC_ALL, 0));
 
@@ -101,7 +116,7 @@ class UtilsDeTest extends UtilsTest
     {
         $current = setlocale(LC_ALL, 0);
         autoLocale('');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }
@@ -112,8 +127,8 @@ class UtilsDeTest extends UtilsTest
     public function testAutoLocaleUnavailable()
     {
         $current = setlocale(LC_ALL, 0);
-        autoLocale('mag_IN');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        autoLocale('mgg_IN');
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }
diff --git a/tests/languages/en/UtilsEnTest.php b/tests/languages/en/UtilsEnTest.php
index 1e297b67..f1e21b9a 100644
--- a/tests/languages/en/UtilsEnTest.php
+++ b/tests/languages/en/UtilsEnTest.php
@@ -6,13 +6,25 @@ use DateTime;
 
 class UtilsEnTest extends UtilsTest
 {
+    /**
+     * Test for international date formatter class. Other tests
+     * will fail without it!
+     */
+    public function testIntlDateFormatter()
+    {
+        $this->assertTrue(class_exists('IntlDateFormatter'));
+    }
+
     /**
      * Test date_format().
      */
     public function testDateFormat()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/January 1, 2017 (at )?10:11:12 AM GMT\+0?3(:00)?/', format_date($date, true, true));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('en_US.UTF-8');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/January 2, 2017 (at )?8:11:12 PM GMT\+0?3(:00)?/', format_date($date, true, true));
+        setlocale(LC_ALL, $current);
     }
 
     /**
@@ -20,26 +32,29 @@ class UtilsEnTest extends UtilsTest
      */
     public function testDateFormatNoTime()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/January 1, 2017/', format_date($date, false, true));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('en_US.UTF-8');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/January 2, 2017/', format_date($date, false, true));
+        setlocale(LC_ALL, $current);
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefault()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertEquals('Sun 01 Jan 2017 10:11:12 AM EAT', format_date($date, true, false));
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_101112');
+        $this->assertEquals('January 2, 2017 10:11:12 AM GMT+03:00', format_date($date, true, false));
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime without time.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefaultNoTime()
     {
         $date = DateTime::createFromFormat('Ymd_His', '20170201_101112');
-        $this->assertEquals('02/01/2017', format_date($date, false, false));
+        $this->assertEquals('February 1, 2017', format_date($date, false, false));
     }
 
     /**
@@ -87,7 +102,7 @@ class UtilsEnTest extends UtilsTest
     public function testAutoLocaleMultipleSecondAvailable()
     {
         $current = setlocale(LC_ALL, 0);
-        $header = 'mag_IN,fr-fr';
+        $header = 'mgg_IN,fr-fr';
         autoLocale($header);
         $this->assertEquals('fr_FR.utf8', setlocale(LC_ALL, 0));
 
@@ -101,7 +116,7 @@ class UtilsEnTest extends UtilsTest
     {
         $current = setlocale(LC_ALL, 0);
         autoLocale('');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }
@@ -112,8 +127,8 @@ class UtilsEnTest extends UtilsTest
     public function testAutoLocaleUnavailable()
     {
         $current = setlocale(LC_ALL, 0);
-        autoLocale('mag_IN');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        autoLocale('mgg_IN');
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }
diff --git a/tests/languages/fr/UtilsFrTest.php b/tests/languages/fr/UtilsFrTest.php
index 3a26250e..799fa5c9 100644
--- a/tests/languages/fr/UtilsFrTest.php
+++ b/tests/languages/fr/UtilsFrTest.php
@@ -6,13 +6,25 @@ use DateTime;
 
 class UtilsFrTest extends UtilsTest
 {
+    /**
+     * Test for international date formatter class. Other tests
+     * will fail without it!
+     */
+    public function testIntlDateFormatter()
+    {
+        $this->assertTrue(class_exists('IntlDateFormatter'));
+    }
+
     /**
      * Test date_format().
      */
     public function testDateFormat()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/1 janvier 2017 (à )?10:11:12 UTC\+0?3(:00)?/', format_date($date));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('fr-fr');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/2 janvier 2017 (à )?20:11:12 UTC\+0?3(:00)?/', format_date($date));
+        setlocale(LC_ALL, $current);
     }
 
     /**
@@ -20,26 +32,29 @@ class UtilsFrTest extends UtilsTest
      */
     public function testDateFormatNoTime()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertRegExp('/1 janvier 2017/', format_date($date, false, true));
+        $current = setlocale(LC_ALL, 0);
+        autoLocale('fr-fr');
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_201112');
+        $this->assertRegExp('/2 janvier 2017/', format_date($date, false, true));
+        setlocale(LC_ALL, $current);
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefault()
     {
-        $date = DateTime::createFromFormat('Ymd_His', '20170101_101112');
-        $this->assertEquals('dim. 01 janv. 2017 10:11:12 EAT', format_date($date, true, false));
+        $date = DateTime::createFromFormat('Ymd_His', '20170102_101112');
+        $this->assertEquals('January 2, 2017 10:11:12 AM GMT+03:00', format_date($date, true, false));
     }
 
     /**
-     * Test date_format() using builtin PHP function strftime without time.
+     * Test date_format() using DateTime
      */
     public function testDateFormatDefaultNoTime()
     {
         $date = DateTime::createFromFormat('Ymd_His', '20170201_101112');
-        $this->assertEquals('01/02/2017', format_date($date, false, false));
+        $this->assertEquals('February 1, 2017', format_date($date, false, false));
     }
 
     /**
@@ -87,7 +102,7 @@ class UtilsFrTest extends UtilsTest
     public function testAutoLocaleMultipleSecondAvailable()
     {
         $current = setlocale(LC_ALL, 0);
-        $header = 'mag_IN,de-de';
+        $header = 'mgg_IN,de-de';
         autoLocale($header);
         $this->assertEquals('de_DE.utf8', setlocale(LC_ALL, 0));
 
@@ -101,7 +116,7 @@ class UtilsFrTest extends UtilsTest
     {
         $current = setlocale(LC_ALL, 0);
         autoLocale('');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }
@@ -112,8 +127,8 @@ class UtilsFrTest extends UtilsTest
     public function testAutoLocaleUnavailable()
     {
         $current = setlocale(LC_ALL, 0);
-        autoLocale('mag_IN');
-        $this->assertEquals('en_US.utf8', setlocale(LC_ALL, 0));
+        autoLocale('mgg_IN');
+        $this->assertEquals('en_US.UTF-8', setlocale(LC_ALL, 0));
 
         setlocale(LC_ALL, $current);
     }