From 7d6a93049399a5ea4d5aaf11417b775d63912afe Mon Sep 17 00:00:00 2001
From: Glynn Quelch <glynn.quelch@gmail.com>
Date: Wed, 10 Jun 2026 12:09:57 +0100
Subject: [PATCH] Add missing tests

---
 .github/workflows/phpunit.yml                 |  47 +++++
 .gitignore                                    |   3 +
 composer.lock                                 | 189 +++++++++++-------
 tests/e2e/fixtures/seed-calendar.php          |  82 ++++++++
 .../frontend/calendar-start-of-week.spec.js   | 151 ++++++++++++++
 tests/phpunit/Calendar/CalendarGridTest.php   | 173 ++++++++++++++++
 6 files changed, 568 insertions(+), 77 deletions(-)
 create mode 100644 .github/workflows/phpunit.yml
 create mode 100644 tests/e2e/fixtures/seed-calendar.php
 create mode 100644 tests/e2e/specs/frontend/calendar-start-of-week.spec.js
 create mode 100644 tests/phpunit/Calendar/CalendarGridTest.php

diff --git a/.github/workflows/phpunit.yml b/.github/workflows/phpunit.yml
new file mode 100644
index 0000000..74fcf87
--- /dev/null
+++ b/.github/workflows/phpunit.yml
@@ -0,0 +1,47 @@
+name: PHPUnit Tests
+
+on:
+  pull_request:
+    branches: [ trunk, develop ]
+
+jobs:
+  phpunit:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.3'
+          tools: composer
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      # Dev dependencies required: test:php runs vendor/bin/phpunit.
+      - name: Install Composer dependencies
+        run: composer install --no-progress --prefer-dist
+
+      - name: Install npm dependencies
+        run: npm ci --force
+
+      # Build so register_block_type finds build/blocks; phpunit.xml.dist sets
+      # convertWarningsToExceptions, so a missing build dir would fail activation.
+      - name: Build plugin assets
+        run: npm run build
+
+      - name: Start wp-env
+        run: npx wp-env start
+
+      - name: Run PHPUnit tests
+        run: npm run test:php
+
+      - name: Stop wp-env
+        if: always()
+        run: npx wp-env stop
diff --git a/.gitignore b/.gitignore
index 6654761..3763620 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,9 @@ build/*
 # wp-env local overrides (per-machine ports etc. — never commit)
 .wp-env.override.json
 
+# Local manual WP-CLI test-data seeder (run by hand, never committed)
+seed-test-events.php
+
 # Playwright
 test-results/
 playwright-report/
diff --git a/composer.lock b/composer.lock
index eac18fa..24165ea 100644
--- a/composer.lock
+++ b/composer.lock
@@ -522,34 +522,34 @@
         },
         {
             "name": "johnbillion/wp-compat",
-            "version": "1.4.0",
+            "version": "1.5.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/johnbillion/wp-compat.git",
-                "reference": "32a2f2406daa5e620e50630e9d4b8b8065d084ab"
+                "reference": "2ccebedbbbc6b6eec3fba4a568cff0a4ec05bf6e"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/johnbillion/wp-compat/zipball/32a2f2406daa5e620e50630e9d4b8b8065d084ab",
-                "reference": "32a2f2406daa5e620e50630e9d4b8b8065d084ab",
+                "url": "https://api.github.com/repos/johnbillion/wp-compat/zipball/2ccebedbbbc6b6eec3fba4a568cff0a4ec05bf6e",
+                "reference": "2ccebedbbbc6b6eec3fba4a568cff0a4ec05bf6e",
                 "shasum": ""
             },
             "require": {
                 "php": ">= 7.4",
                 "phpstan/phpstan": "^2.0",
-                "wp-hooks/wordpress-core": "^1.11"
+                "wp-hooks/wordpress-core": "^1.12"
             },
             "require-dev": {
                 "dealerdirect/phpcodesniffer-composer-installer": "^0.7.0",
                 "johnbillion/plugin-infrastructure": "dev-trunk",
                 "nikic/php-parser": "^5.1",
-                "php-stubs/wordpress-stubs": "^6.9",
+                "php-stubs/wordpress-stubs": "~7.0.0",
                 "phpstan/phpstan-deprecation-rules": "2.0.0",
                 "phpstan/phpstan-phpunit": "2.0.1",
                 "phpstan/phpstan-strict-rules": "2.0.0",
                 "phpunit/phpunit": "^9.0",
                 "roots/wordpress-core-installer": "1.100.0",
-                "roots/wordpress-full": "*",
+                "roots/wordpress-full": "~7.0.0",
                 "wp-coding-standards/wpcs": "3.1.0"
             },
             "suggest": {
@@ -596,7 +596,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-12-04T10:54:35+00:00"
+            "time": "2026-05-22T14:13:03+00:00"
         },
         {
             "name": "myclabs/deep-copy",
@@ -899,16 +899,16 @@
         },
         {
             "name": "php-stubs/wordpress-stubs",
-            "version": "v6.9.1",
+            "version": "v6.9.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/php-stubs/wordpress-stubs.git",
-                "reference": "f12220f303e0d7c0844c0e5e957b0c3cee48d2f7"
+                "reference": "90a9412826b9944f93b10bf41d795b5fe68abcd5"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-stubs/wordpress-stubs/zipball/f12220f303e0d7c0844c0e5e957b0c3cee48d2f7",
-                "reference": "f12220f303e0d7c0844c0e5e957b0c3cee48d2f7",
+                "url": "https://api.github.com/repos/php-stubs/wordpress-stubs/zipball/90a9412826b9944f93b10bf41d795b5fe68abcd5",
+                "reference": "90a9412826b9944f93b10bf41d795b5fe68abcd5",
                 "shasum": ""
             },
             "conflict": {
@@ -918,7 +918,7 @@
                 "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
                 "nikic/php-parser": "^5.5",
                 "php": "^7.4 || ^8.0",
-                "php-stubs/generator": "^0.8.3",
+                "php-stubs/generator": "^0.8.6",
                 "phpdocumentor/reflection-docblock": "^6.0",
                 "phpstan/phpstan": "^2.1",
                 "phpunit/phpunit": "^9.5",
@@ -945,9 +945,9 @@
             ],
             "support": {
                 "issues": "https://github.com/php-stubs/wordpress-stubs/issues",
-                "source": "https://github.com/php-stubs/wordpress-stubs/tree/v6.9.1"
+                "source": "https://github.com/php-stubs/wordpress-stubs/tree/v6.9.4"
             },
-            "time": "2026-02-03T19:29:21+00:00"
+            "time": "2026-05-01T20:36:01+00:00"
         },
         {
             "name": "phpcompatibility/php-compatibility",
@@ -1470,11 +1470,11 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "2.1.54",
+            "version": "2.2.0",
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/8be50c3992107dc837b17da4d140fbbdf9a5c5bd",
-                "reference": "8be50c3992107dc837b17da4d140fbbdf9a5c5bd",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/b4cd98348c809924f62bb9cc8c047f5e73bc9a58",
+                "reference": "b4cd98348c809924f62bb9cc8c047f5e73bc9a58",
                 "shasum": ""
             },
             "require": {
@@ -1497,6 +1497,17 @@
             "license": [
                 "MIT"
             ],
+            "authors": [
+                {
+                    "name": "Ondřej Mirtes"
+                },
+                {
+                    "name": "Markus Staab"
+                },
+                {
+                    "name": "Vincent Langlet"
+                }
+            ],
             "description": "PHPStan - PHP Static Analysis Tool",
             "keywords": [
                 "dev",
@@ -1519,7 +1530,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2026-04-29T13:31:09+00:00"
+            "time": "2026-05-28T08:22:43+00:00"
         },
         {
             "name": "phpstan/phpstan-deprecation-rules",
@@ -2161,12 +2172,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/Roave/SecurityAdvisories.git",
-                "reference": "16706d82a6f250e56047a9e95791a92a8a29f791"
+                "reference": "d6992473ee5e901c44ba7e8c82b3445692d04794"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/Roave/SecurityAdvisories/zipball/16706d82a6f250e56047a9e95791a92a8a29f791",
-                "reference": "16706d82a6f250e56047a9e95791a92a8a29f791",
+                "url": "https://api.github.com/repos/Roave/SecurityAdvisories/zipball/d6992473ee5e901c44ba7e8c82b3445692d04794",
+                "reference": "d6992473ee5e901c44ba7e8c82b3445692d04794",
                 "shasum": ""
             },
             "conflict": {
@@ -2221,7 +2232,7 @@
                 "auth0/login": "<=7.20",
                 "auth0/symfony": "<=5.7",
                 "auth0/wordpress": "<=5.5",
-                "automad/automad": "<2.0.0.0-alpha5",
+                "automad/automad": "<=2.0.0.0-beta27",
                 "automattic/jetpack": "<9.8",
                 "awesome-support/awesome-support": "<=6.0.7",
                 "aws/aws-sdk-php": "<=3.371.3",
@@ -2281,13 +2292,13 @@
                 "cesnet/simplesamlphp-module-proxystatistics": "<3.1",
                 "chriskacerguis/codeigniter-restserver": "<=2.7.1",
                 "chrome-php/chrome": "<1.14",
-                "ci4-cms-erp/ci4ms": "<=0.31.7",
+                "ci4-cms-erp/ci4ms": "<=0.31.8",
                 "civicrm/civicrm-core": ">=4.2,<4.2.9|>=4.3,<4.3.3",
                 "ckeditor/ckeditor": "<4.25",
                 "clickstorm/cs-seo": ">=6,<6.8|>=7,<7.5|>=8,<8.4|>=9,<9.3",
                 "co-stack/fal_sftp": "<0.2.6",
-                "cockpit-hq/cockpit": "<2.14",
-                "code16/sharp": "<9.20",
+                "cockpit-hq/cockpit": "<=2.14",
+                "code16/sharp": "<9.22",
                 "codeception/codeception": "<3.1.3|>=4,<4.1.22",
                 "codeigniter/framework": "<3.1.10",
                 "codeigniter4/framework": "<4.6.2",
@@ -2412,6 +2423,7 @@
                 "erusev/parsedown": "<1.7.2",
                 "ether/logs": "<3.0.4",
                 "evolutioncms/evolution": "<=3.2.3",
+                "evoweb/sf-register": "<13.2.4|>=14,<14.0.2",
                 "exceedone/exment": "<4.4.3|>=5,<5.0.3",
                 "exceedone/laravel-admin": "<2.2.3|==3",
                 "ezsystems/demobundle": ">=5.4,<5.4.6.1-dev",
@@ -2476,6 +2488,7 @@
                 "friendsofsymfony1/symfony1": ">=1.1,<1.5.19",
                 "friendsoftypo3/mediace": ">=7.6.2,<7.6.5",
                 "friendsoftypo3/openid": ">=4.5,<4.5.31|>=4.7,<4.7.16|>=6,<6.0.11|>=6.1,<6.1.6",
+                "friendsoftypo3/tt-address": "<8.1.2|>=9,<9.1.1|>=10,<10.0.1",
                 "froala/wysiwyg-editor": "<=4.3",
                 "frosh/adminer-platform": "<2.2.1",
                 "froxlor/froxlor": "<2.3.6",
@@ -2484,13 +2497,13 @@
                 "funadmin/funadmin": "<=7.1.0.0-RC6",
                 "gaoming13/wechat-php-sdk": "<=1.10.2",
                 "genix/cms": "<=1.1.11",
-                "georgringer/news": "<1.3.3",
+                "georgringer/news": "<11.4.4|>=12,<12.3.2|>=13,<13.0.2|>=14,<14.0.3",
                 "geshi/geshi": "<=1.0.9.1",
                 "getformwork/formwork": "<=2.3.3",
                 "getgrav/grav": "<=2.0.0.0-RC1",
                 "getgrav/grav-plugin-api": "<1.0.0.0-beta15",
                 "getgrav/grav-plugin-form": "<9.1",
-                "getkirby/cms": "<4.9|>=5,<5.4",
+                "getkirby/cms": "<=4.9|>=5,<=5.4",
                 "getkirby/kirby": "<3.9.8.3-dev|>=3.10,<3.10.1.2-dev|>=4,<4.7.1",
                 "getkirby/panel": "<2.5.14",
                 "getkirby/starterkit": "<=3.7.0.2",
@@ -2592,13 +2605,14 @@
                 "kimai/kimai": "<=2.55",
                 "kitodo/presentation": "<3.2.3|>=3.3,<3.3.4",
                 "klaviyo/magento2-extension": ">=1,<3",
-                "knplabs/knp-snappy": "<=1.4.2",
+                "knplabs/knp-snappy": "<=1.7",
                 "kohana/core": "<3.3.3",
                 "koillection/koillection": "<1.6.12",
                 "krayin/laravel-crm": "<=2.2",
                 "kreait/firebase-php": ">=3.2,<3.8.1",
                 "kumbiaphp/kumbiapp": "<=1.1.1",
                 "la-haute-societe/tcpdf": "<6.2.22",
+                "laktak/hjson": "<2.3",
                 "laminas/laminas-diactoros": "<2.18.1|==2.19|==2.20|==2.21|==2.22|==2.23|>=2.24,<2.24.2|>=2.25,<2.25.2",
                 "laminas/laminas-form": "<2.17.1|>=3,<3.0.2|>=3.1,<3.1.1",
                 "laminas/laminas-http": "<2.14.2",
@@ -2683,6 +2697,7 @@
                 "miraheze/ts-portal": "<=33",
                 "mittwald/typo3_forum": "<1.2.1",
                 "mix/mix": ">=2,<=2.2.17",
+                "mmc/ceselector": "<3.0.3|>=4,<4.0.2|>=5,<5.0.1|>=6,<6.0.1",
                 "mobiledetect/mobiledetectlib": "<2.8.32",
                 "modx/revolution": "<=3.1",
                 "mojo42/jirafeau": "<4.4",
@@ -2786,7 +2801,7 @@
                 "phpmailer/phpmailer": "<6.5",
                 "phpmussel/phpmussel": ">=1,<1.6",
                 "phpmyadmin/phpmyadmin": "<5.2.2",
-                "phpmyfaq/phpmyfaq": "<=4.1.1",
+                "phpmyfaq/phpmyfaq": "<4.1.3",
                 "phpoffice/common": "<0.2.9",
                 "phpoffice/math": "<=0.2",
                 "phpoffice/phpexcel": "<=1.8.2",
@@ -2801,14 +2816,14 @@
                 "phpxmlrpc/phpxmlrpc": "<4.9.2",
                 "phraseanet/phraseanet": "==4.0.3",
                 "pi/pi": "<=2.5",
-                "pimcore/admin-ui-classic-bundle": "<=1.7.15|>=2.0.0.0-RC1-dev,<=2.2.2",
+                "pimcore/admin-ui-classic-bundle": "<=2.3.5",
                 "pimcore/customer-management-framework-bundle": "<4.2.1",
                 "pimcore/data-hub": "<1.2.4",
                 "pimcore/data-importer": "<1.8.9|>=1.9,<1.9.3",
                 "pimcore/demo": "<10.3",
                 "pimcore/ecommerce-framework-bundle": "<1.0.10",
                 "pimcore/perspective-editor": "<1.5.1",
-                "pimcore/pimcore": "<=11.5.14.1|>=12,<12.3.3|==12.3.3",
+                "pimcore/pimcore": "<=12.3.6",
                 "pimcore/web2print-tools-bundle": "<=5.2.1|>=6.0.0.0-RC1-dev,<=6.1",
                 "piwik/piwik": "<1.11",
                 "pixelfed/pixelfed": "<0.12.5",
@@ -2834,7 +2849,7 @@
                 "propel/propel": ">=2.0.0.0-alpha1,<=2.0.0.0-alpha7",
                 "propel/propel1": ">=1,<=1.7.1",
                 "psy/psysh": "<=0.11.22|>=0.12,<=0.12.18",
-                "pterodactyl/panel": "<1.12.1",
+                "pterodactyl/panel": "<1.12.3",
                 "ptheofan/yii2-statemachine": ">=2.0.0.0-RC1-dev,<=2",
                 "ptrofimov/beanstalk_console": "<1.7.14",
                 "pubnub/pubnub": "<6.1",
@@ -2877,9 +2892,11 @@
                 "scheb/two-factor-bundle": "<3.26|>=4,<4.11",
                 "sensiolabs/connect": "<4.2.3",
                 "serluck/phpwhois": "<=4.2.6",
-                "setasign/fpdi": "<2.6.4",
+                "setasign/fpdi": "<2.6.7",
                 "sfroemken/url_redirect": "<=1.2.1",
                 "sheng/yiicms": "<1.2.1",
+                "shopper/cart": "<2.8",
+                "shopper/framework": "<2.8",
                 "shopware/core": "<6.6.10.15-dev|>=6.7,<6.7.8.1-dev",
                 "shopware/platform": "<6.6.10.15-dev|>=6.7,<6.7.8.1-dev",
                 "shopware/production": "<=6.3.5.2",
@@ -2911,6 +2928,7 @@
                 "simplesamlphp/saml2": "<=4.16.15|>=5.0.0.0-alpha1,<=5.0.0.0-alpha19",
                 "simplesamlphp/saml2-legacy": "<=4.16.15",
                 "simplesamlphp/simplesamlphp": "<1.18.6",
+                "simplesamlphp/simplesamlphp-module-casserver": "<=7.0.2",
                 "simplesamlphp/simplesamlphp-module-infocard": "<1.0.1",
                 "simplesamlphp/simplesamlphp-module-openid": "<1",
                 "simplesamlphp/simplesamlphp-module-openidprovider": "<0.9",
@@ -2932,6 +2950,7 @@
                 "soosyze/soosyze": "<=2",
                 "spatie/browsershot": "<5.0.5",
                 "spatie/image-optimizer": "<1.7.3",
+                "spatie/schema-org": ">=3.23.1,<4.0.2",
                 "spencer14420/sp-php-email-handler": "<1",
                 "spipu/html2pdf": "<5.2.8",
                 "spiral/roadrunner": "<2025.1",
@@ -2943,14 +2962,14 @@
                 "starcitizentools/short-description": ">=4,<4.0.1",
                 "starcitizentools/tabber-neue": ">=1.9.1,<2.7.2|>=3,<3.1.1",
                 "starcitizenwiki/embedvideo": "<=4",
-                "statamic/cms": "<5.73.21|>=6,<6.15",
+                "statamic/cms": "<5.73.22|>=6,<6.18.1",
                 "stormpath/sdk": "<9.9.99",
                 "studio-42/elfinder": "<=2.1.67",
                 "studiomitte/friendlycaptcha": "<0.1.4",
                 "subhh/libconnect": "<7.0.8|>=8,<8.1",
                 "sukohi/surpass": "<1",
                 "sulu/form-bundle": ">=2,<2.5.3",
-                "sulu/sulu": "<2.6.22|>=3,<3.0.5",
+                "sulu/sulu": "<=2.6.22|>=3,<=3.0.5",
                 "sumocoders/framework-user-bundle": "<1.4",
                 "superbig/craft-audit": "<3.0.2",
                 "svewap/a21glossary": "<=0.4.10",
@@ -2968,42 +2987,53 @@
                 "symbiote/silverstripe-seed": "<6.0.3",
                 "symbiote/silverstripe-versionedfiles": "<=2.0.3",
                 "symfont/process": ">=0",
-                "symfony/cache": ">=3.1,<3.4.35|>=4,<4.2.12|>=4.3,<4.3.8",
+                "symfony/cache": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symfony/dependency-injection": ">=2,<2.0.17|>=2.7,<2.7.51|>=2.8,<2.8.50|>=3,<3.4.26|>=4,<4.1.12|>=4.2,<4.2.7",
+                "symfony/dom-crawler": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symfony/error-handler": ">=4.4,<4.4.4|>=5,<5.0.4",
                 "symfony/form": ">=2.3,<2.3.35|>=2.4,<2.6.12|>=2.7,<2.7.50|>=2.8,<2.8.49|>=3,<3.4.20|>=4,<4.0.15|>=4.1,<4.1.9|>=4.2,<4.2.1",
                 "symfony/framework-bundle": ">=2,<2.3.18|>=2.4,<2.4.8|>=2.5,<2.5.2|>=2.7,<2.7.51|>=2.8,<2.8.50|>=3,<3.4.26|>=4,<4.1.12|>=4.2,<4.2.7|>=5.3.14,<5.3.15|>=5.4.3,<5.4.4|>=6.0.3,<6.0.4",
-                "symfony/http-client": ">=4.3,<5.4.47|>=6,<6.4.15|>=7,<7.1.8",
-                "symfony/http-foundation": "<5.4.50|>=6,<6.4.29|>=7,<7.3.7",
-                "symfony/http-kernel": ">=2,<4.4.50|>=5,<5.4.20|>=6,<6.0.20|>=6.1,<6.1.12|>=6.2,<6.2.6",
+                "symfony/html-sanitizer": ">=6.1,<6.4.41|>=7,<7.4.13|>=8,<8.0.13",
+                "symfony/http-client": ">=4.3,<5.4.53|>=6,<6.4.15|>=7,<7.1.8",
+                "symfony/http-foundation": "<5.4.50|>=6,<6.4.41|>=7,<7.4.13|>=8,<8.0.13",
+                "symfony/http-kernel": ">=2,<4.4.50|>=5,<5.4.20|>=6,<6.0.20|>=6.1,<6.1.12|>=6.2,<6.2.6|>=7.4,<7.4.12|>=8,<8.0.12",
                 "symfony/intl": ">=2.7,<2.7.38|>=2.8,<2.8.31|>=3,<3.2.14|>=3.3,<3.3.13",
+                "symfony/json-path": ">=7.3,<7.4.12|>=8,<8.0.12",
+                "symfony/lox24-notifier": ">=7.1,<7.4.12|>=8,<8.0.12",
+                "symfony/mailer": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
+                "symfony/mailjet-mailer": ">=6.4,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
+                "symfony/mailomat-mailer": ">=7.2,<7.4.13|>=8,<8.0.13",
+                "symfony/mailtrap-mailer": ">=7.2,<7.4.12|>=8,<8.0.12",
                 "symfony/maker-bundle": ">=1.27,<1.29.2|>=1.30,<1.31.1",
-                "symfony/mime": ">=4.3,<4.3.8",
+                "symfony/mime": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
+                "symfony/monolog-bridge": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symfony/phpunit-bridge": ">=2.8,<2.8.50|>=3,<3.4.26|>=4,<4.1.12|>=4.2,<4.2.7",
-                "symfony/polyfill": ">=1,<1.10",
+                "symfony/polyfill": ">=1,<1.10|>=1.17.1,<1.38.1",
+                "symfony/polyfill-intl-idn": ">=1.17.1,<1.38.1",
                 "symfony/polyfill-php55": ">=1,<1.10",
                 "symfony/process": "<5.4.51|>=6,<6.4.33|>=7,<7.1.7|>=7.3,<7.3.11|>=7.4,<7.4.5|>=8,<8.0.5",
                 "symfony/proxy-manager-bridge": ">=2.7,<2.7.51|>=2.8,<2.8.50|>=3,<3.4.26|>=4,<4.1.12|>=4.2,<4.2.7",
-                "symfony/routing": ">=2,<2.0.19",
-                "symfony/runtime": ">=5.3,<5.4.46|>=6,<6.4.14|>=7,<7.1.7",
+                "symfony/routing": "<5.4.53|>=6,<6.4.41|>=7,<7.4.13|>=8,<8.0.13",
+                "symfony/runtime": ">=5.3,<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symfony/security": ">=2,<2.7.51|>=2.8,<3.4.49|>=4,<4.4.24|>=5,<5.2.8",
                 "symfony/security-bundle": ">=2,<4.4.50|>=5,<5.4.20|>=6,<6.0.20|>=6.1,<6.1.12|>=6.2,<6.4.10|>=7,<7.0.10|>=7.1,<7.1.3",
                 "symfony/security-core": ">=2.4,<2.6.13|>=2.7,<2.7.9|>=2.7.30,<2.7.32|>=2.8,<3.4.49|>=4,<4.4.24|>=5,<5.2.9",
                 "symfony/security-csrf": ">=2.4,<2.7.48|>=2.8,<2.8.41|>=3,<3.3.17|>=3.4,<3.4.11|>=4,<4.0.11",
                 "symfony/security-guard": ">=2.8,<3.4.48|>=4,<4.4.23|>=5,<5.2.8",
-                "symfony/security-http": ">=2.3,<2.3.41|>=2.4,<2.7.51|>=2.8,<2.8.50|>=3,<3.4.26|>=4,<4.2.12|>=4.3,<4.3.8|>=4.4,<4.4.7|>=5,<5.0.7|>=5.1,<5.2.8|>=5.3,<5.4.47|>=6,<6.4.15|>=7,<7.1.8",
+                "symfony/security-http": "<5.4.53|>=6,<6.4.41|>=7,<7.4.13|>=8,<8.0.13",
                 "symfony/serializer": ">=2,<2.0.11|>=4.1,<4.4.35|>=5,<5.3.12",
-                "symfony/symfony": "<5.4.51|>=6,<6.4.33|>=7,<7.3.11|>=7.4,<7.4.5|>=8,<8.0.5",
+                "symfony/symfony": "<5.4.53|>=6,<6.4.41|>=7,<7.4.13|>=8,<8.0.13",
                 "symfony/translation": ">=2,<2.0.17",
-                "symfony/twig-bridge": ">=2,<4.4.51|>=5,<5.4.31|>=6,<6.3.8",
+                "symfony/twig-bridge": ">=2,<4.4.51|>=5,<5.4.31|>=6,<6.3.8|>=6.4.24,<6.4.40",
+                "symfony/twilio-notifier": ">=6.4,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symfony/ux-autocomplete": "<2.11.2",
                 "symfony/ux-live-component": "<2.25.1",
                 "symfony/ux-twig-component": "<2.25.1",
                 "symfony/validator": "<5.4.43|>=6,<6.4.11|>=7,<7.1.4",
                 "symfony/var-exporter": ">=4.2,<4.2.12|>=4.3,<4.3.8",
-                "symfony/web-profiler-bundle": ">=2,<2.3.19|>=2.4,<2.4.9|>=2.5,<2.5.4",
+                "symfony/web-profiler-bundle": ">=2,<2.3.19|>=2.4,<2.4.9|>=2.5,<2.5.4|>=7.2.9,<7.4.12|>=8,<8.0.12",
                 "symfony/webhook": ">=6.3,<6.3.8",
-                "symfony/yaml": ">=2,<2.0.22|>=2.1,<2.1.7|>=2.2.0.0-beta1,<2.2.0.0-beta2",
+                "symfony/yaml": "<5.4.52|>=6,<6.4.40|>=7,<7.4.12|>=8,<8.0.12",
                 "symphonycms/symphony-2": "<2.6.4",
                 "t3/dce": "<0.11.5|>=2.2,<2.6.2",
                 "t3g/svg-sanitizer": "<1.0.3",
@@ -3017,7 +3047,7 @@
                 "thelia/thelia": ">=2.1,<2.1.3",
                 "theonedemon/phpwhois": "<=4.2.5",
                 "thinkcmf/thinkcmf": "<6.0.8",
-                "thorsten/phpmyfaq": "<=4.1.1",
+                "thorsten/phpmyfaq": "<4.1.3",
                 "tikiwiki/tiki-manager": "<=17.1",
                 "timber/timber": ">=0.16.6,<1.23.1|>=1.24,<1.24.1|>=2,<2.1",
                 "tinymce/tinymce": "<7.2",
@@ -3025,16 +3055,20 @@
                 "titon/framework": "<9.9.99",
                 "tltneon/lgsl": "<7",
                 "tobiasbg/tablepress": "<=2.0.0.0-RC1",
+                "tomasnorre/crawler": "<11.0.13|>=12,<12.0.11",
                 "topthink/framework": "<6.0.17|>=6.1,<=8.0.4",
                 "topthink/think": "<=6.1.1",
                 "topthink/thinkphp": "<=3.2.3|>=6.1.3,<=8.0.4",
                 "torrentpier/torrentpier": "<=2.8.8",
-                "tpwd/ke_search": "<4.0.3|>=4.1,<4.6.6|>=5,<5.0.2",
+                "tpwd/ke_search": "<5.6.2|>=6,<6.6.1|>=7,<7.0.1",
                 "tribalsystems/zenario": "<=9.7.61188",
                 "truckersmp/phpwhois": "<=4.3.1",
                 "ttskch/pagination-service-provider": "<1",
                 "twbs/bootstrap": "<3.4.1|>=4,<4.3.1",
-                "twig/twig": "<3.11.2|>=3.12,<3.14.1|>=3.16,<3.19",
+                "twig/cssinliner-extra": "<3.26",
+                "twig/intl-extra": "<3.26",
+                "twig/markdown-extra": "<3.26",
+                "twig/twig": "<3.27",
                 "typicms/core": "<16.1.7",
                 "typo3/cms": "<9.5.29|>=10,<10.4.35|>=11,<11.5.23|>=12,<12.2",
                 "typo3/cms-backend": "<4.1.14|>=4.2,<4.2.15|>=4.3,<4.3.7|>=4.4,<4.4.4|>=7,<=7.6.50|>=8,<=8.7.39|>=9,<9.5.55|>=10,<=10.4.54|>=11,<=11.5.48|>=12,<=12.4.40|>=13,<=13.4.22|>=14,<=14.0.1|==14.2",
@@ -3076,7 +3110,7 @@
                 "uvdesk/core-framework": "<=1.1.1",
                 "vanilla/safecurl": "<0.9.2",
                 "verbb/comments": "<1.5.5",
-                "verbb/formie": "<=2.1.43",
+                "verbb/formie": "<2.2.20|>=3.0.0.0-beta1,<3.1.24",
                 "verbb/image-resizer": "<2.0.9",
                 "verbb/knock-knock": "<1.2.8",
                 "verot/class.upload.php": "<=2.1.6",
@@ -3124,7 +3158,7 @@
                 "xpressengine/xpressengine": "<3.0.15",
                 "yab/quarx": "<2.4.5",
                 "yansongda/pay": "<=3.7.19",
-                "yeswiki/yeswiki": "<=4.6",
+                "yeswiki/yeswiki": "<4.6.4",
                 "yetiforce/yetiforce-crm": "<6.5",
                 "yidashi/yii2cmf": "<=2",
                 "yii2mod/yii2-cms": "<1.9.2",
@@ -3219,7 +3253,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2026-05-14T13:38:25+00:00"
+            "time": "2026-05-27T21:36:42+00:00"
         },
         {
             "name": "sebastian/cli-parser",
@@ -4444,16 +4478,16 @@
         },
         {
             "name": "symfony/dependency-injection",
-            "version": "v7.4.10",
+            "version": "v7.4.13",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/dependency-injection.git",
-                "reference": "4eb0d9dfa9d4f7c59216baf49b3ed6b1fb72293d"
+                "reference": "f299e20ce983be6c0744952533c6dfeaaa1448e2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/4eb0d9dfa9d4f7c59216baf49b3ed6b1fb72293d",
-                "reference": "4eb0d9dfa9d4f7c59216baf49b3ed6b1fb72293d",
+                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/f299e20ce983be6c0744952533c6dfeaaa1448e2",
+                "reference": "f299e20ce983be6c0744952533c6dfeaaa1448e2",
                 "shasum": ""
             },
             "require": {
@@ -4504,7 +4538,7 @@
             "description": "Allows you to standardize and centralize the way objects are constructed in your application",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/dependency-injection/tree/v7.4.10"
+                "source": "https://github.com/symfony/dependency-injection/tree/v7.4.13"
             },
             "funding": [
                 {
@@ -4524,7 +4558,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2026-05-06T11:55:30+00:00"
+            "time": "2026-05-20T14:07:29+00:00"
         },
         {
             "name": "symfony/filesystem",
@@ -4681,16 +4715,16 @@
         },
         {
             "name": "symfony/polyfill-mbstring",
-            "version": "v1.37.0",
+            "version": "v1.38.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/polyfill-mbstring.git",
-                "reference": "6a21eb99c6973357967f6ce3708cd55a6bec6315"
+                "reference": "14c5439eec4ccff081ac14eca2dc57feb2a66d92"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/6a21eb99c6973357967f6ce3708cd55a6bec6315",
-                "reference": "6a21eb99c6973357967f6ce3708cd55a6bec6315",
+                "url": "https://api.github.com/repos/symfony/polyfill-mbstring/zipball/14c5439eec4ccff081ac14eca2dc57feb2a66d92",
+                "reference": "14c5439eec4ccff081ac14eca2dc57feb2a66d92",
                 "shasum": ""
             },
             "require": {
@@ -4742,7 +4776,7 @@
                 "shim"
             ],
             "support": {
-                "source": "https://github.com/symfony/polyfill-mbstring/tree/v1.37.0"
+                "source": "https://github.com/symfony/polyfill-mbstring/tree/v1.38.1"
             },
             "funding": [
                 {
@@ -4762,7 +4796,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2026-04-10T17:25:58+00:00"
+            "time": "2026-05-26T12:51:13+00:00"
         },
         {
             "name": "symfony/service-contracts",
@@ -5113,16 +5147,16 @@
         },
         {
             "name": "wp-hooks/wordpress-core",
-            "version": "1.11.0",
+            "version": "1.12.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/wp-hooks/wordpress-core-hooks.git",
-                "reference": "610a3721216797daa72a16044c40938ac040551a"
+                "reference": "0ba438bdd4c99b6613eb8459feb0a4f6d2d7082c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/wp-hooks/wordpress-core-hooks/zipball/610a3721216797daa72a16044c40938ac040551a",
-                "reference": "610a3721216797daa72a16044c40938ac040551a",
+                "url": "https://api.github.com/repos/wp-hooks/wordpress-core-hooks/zipball/0ba438bdd4c99b6613eb8459feb0a4f6d2d7082c",
+                "reference": "0ba438bdd4c99b6613eb8459feb0a4f6d2d7082c",
                 "shasum": ""
             },
             "replace": {
@@ -5132,7 +5166,7 @@
                 "erusev/parsedown": "1.8.0-beta-7",
                 "oomphinc/composer-installers-extender": "^2",
                 "roots/wordpress-core-installer": "^1.0.0",
-                "roots/wordpress-full": "6.9",
+                "roots/wordpress-full": "7.0",
                 "wp-hooks/generator": "1.0.0"
             },
             "type": "library",
@@ -5142,6 +5176,7 @@
                         "wp-admin/includes/deprecated.php",
                         "wp-admin/includes/ms-deprecated.php",
                         "wp-content/",
+                        "wp-includes/build/pages/",
                         "wp-includes/deprecated.php",
                         "wp-includes/ID3/",
                         "wp-includes/ms-deprecated.php",
@@ -5183,7 +5218,7 @@
             "description": "All the actions and filters from WordPress core in machine-readable JSON format.",
             "support": {
                 "issues": "https://github.com/wp-hooks/wordpress-core-hooks/issues",
-                "source": "https://github.com/wp-hooks/wordpress-core-hooks/tree/1.11.0"
+                "source": "https://github.com/wp-hooks/wordpress-core-hooks/tree/1.12.0"
             },
             "funding": [
                 {
@@ -5191,7 +5226,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-12-03T22:11:59+00:00"
+            "time": "2026-05-22T10:28:41+00:00"
         },
         {
             "name": "yoast/phpunit-polyfills",
@@ -5265,10 +5300,10 @@
     },
     "prefer-stable": false,
     "prefer-lowest": false,
-    "platform": [],
-    "platform-dev": [],
+    "platform": {},
+    "platform-dev": {},
     "platform-overrides": {
         "php": "8.3"
     },
-    "plugin-api-version": "2.2.0"
+    "plugin-api-version": "2.6.0"
 }
diff --git a/tests/e2e/fixtures/seed-calendar.php b/tests/e2e/fixtures/seed-calendar.php
new file mode 100644
index 0000000..8e1fbbb
--- /dev/null
+++ b/tests/e2e/fixtures/seed-calendar.php
@@ -0,0 +1,82 @@
+<?php
+/**
+ * Seeder for the calendar start-of-week front-end e2e spec.
+ *
+ * Run via: wp eval-file tests/e2e/fixtures/seed-calendar.php <0-6>
+ *
+ * Sets the WordPress `start_of_week` option to the value passed as the first
+ * positional argument (default 1 = Monday), then seeds a single published
+ * se-event with a child se-event-date dated *today* so the current month has
+ * an event and the calendar renders that month's grid (rather than the
+ * "No Events Scheduled" state or jumping to another month). Creates a page
+ * holding the real calendar block and echoes its ID for the spec to navigate
+ * to. Idempotent — wipes prior run first.
+ *
+ * @package Simple_Events
+ */
+
+$prefix = 'E2ECAL';
+
+// First positional arg from `wp eval-file` is the start_of_week to set.
+$start_of_week = isset( $args[0] ) && '' !== $args[0] ? (int) $args[0] : 1;
+$start_of_week = max( 0, min( 6, $start_of_week ) );
+
+update_option( 'start_of_week', $start_of_week );
+
+// Full clean slate: delete EVERY se-event and se-event-date (any status) so the
+// calendar only ever sees this seeder's data, plus a prior run's page.
+$wipe = get_posts(
+	array(
+		'post_type'   => array( 'se-event', 'se-event-date' ),
+		'post_status' => 'any',
+		'numberposts' => -1,
+	)
+);
+foreach ( $wipe as $p ) {
+	wp_delete_post( $p->ID, true );
+}
+foreach ( get_posts(
+	array(
+		'post_type'   => 'page',
+		'post_status' => 'any',
+		'numberposts' => -1,
+		's'           => $prefix,
+	)
+) as $p ) {
+	wp_delete_post( $p->ID, true );
+}
+
+// Event-info block in content so the save_post cleanup hook keeps child dates.
+$event_content = '<!-- wp:simple-events/event-info /-->';
+
+$event_id = wp_insert_post(
+	array(
+		'post_type'    => 'se-event',
+		'post_status'  => 'publish',
+		'post_title'   => $prefix . ' EVENT',
+		'post_content' => $event_content,
+	)
+);
+
+// Date today (noon, to stay safely inside the current month) so the current
+// month has an event and the grid renders.
+$ts = strtotime( 'today noon' );
+se_event_create_event_date(
+	$event_id,
+	array(
+		'start_date' => $ts,
+		'end_date'   => $ts + 7200,
+		'all_day'    => false,
+	)
+);
+
+$page_id = wp_insert_post(
+	array(
+		'post_type'    => 'page',
+		'post_status'  => 'publish',
+		'post_title'   => $prefix . ' PAGE',
+		'post_content' => '<!-- wp:simple-events/calendar /-->',
+	)
+);
+
+echo (int) $page_id;
diff --git a/tests/e2e/specs/frontend/calendar-start-of-week.spec.js b/tests/e2e/specs/frontend/calendar-start-of-week.spec.js
new file mode 100644
index 0000000..38de521
--- /dev/null
+++ b/tests/e2e/specs/frontend/calendar-start-of-week.spec.js
@@ -0,0 +1,151 @@
+const { test, expect } = require( '@playwright/test' );
+const { execSync } = require( 'child_process' );
+const path = require( 'path' );
+
+const BASE_URL = process.env.WP_BASE_URL || 'http://localhost:8888';
+
+const WEEKDAYS = [
+	'Sunday',
+	'Monday',
+	'Tuesday',
+	'Wednesday',
+	'Thursday',
+	'Friday',
+	'Saturday',
+];
+
+// Regression cases for the calendar day-of-week fix (PR #76). The old
+// Monday-only offset maths broke Sunday- and Saturday-start weeks, so those are
+// the representative values exercised here alongside the Monday default.
+const START_OF_WEEKS = [ 0, 1, 6 ]; // Sunday, Monday, Saturday.
+
+/**
+ * Seed the calendar page for a given start_of_week and return its page ID.
+ *
+ * @param {number} startOfWeek 0 (Sunday) through 6 (Saturday).
+ * @return {string} The seeded page ID.
+ */
+function seedCalendar( startOfWeek ) {
+	const out = execSync(
+		`npx wp-env run cli --env-cwd='wp-content/plugins/simple-events' -- wp eval-file tests/e2e/fixtures/seed-calendar.php ${ startOfWeek }`,
+		{ encoding: 'utf8' }
+	);
+	const m = out.match( /(\d+)\s*$/m );
+	if ( ! m ) {
+		throw new Error( 'Seeder did not return a page ID. Output:\n' + out );
+	}
+	return m[ 1 ];
+}
+
+/**
+ * Weekday (0=Sun..6=Sat) for a yyyy-mm-dd datetime attribute, read in UTC so
+ * the test machine's timezone can't shift the day.
+ *
+ * @param {string} datetime A `Y-m-d` string from a <time datetime> attribute.
+ * @return {number} Weekday index.
+ */
+function weekdayOf( datetime ) {
+	return new Date( `${ datetime }T00:00:00Z` ).getUTCDay();
+}
+
+test.describe( 'calendar grid respects start_of_week', () => {
+	for ( const startOfWeek of START_OF_WEEKS ) {
+		test( `start_of_week=${ startOfWeek } (${ WEEKDAYS[ startOfWeek ] }) aligns header and grid`, async ( {
+			page,
+		} ) => {
+			const pageId = seedCalendar( startOfWeek );
+			await page.goto( `${ BASE_URL }/?page_id=${ pageId }` );
+
+			// Wait for the server-rendered grid (event seeded today ⇒ weeks render).
+			await page
+				.locator( '.simple-events-calendar-month__week' )
+				.first()
+				.waitFor();
+
+			// --- Header columns: 7 columns, rotated to start on start_of_week. ---
+			const headerLabels = await page
+				.locator( '.simple-events-calendar-month__header-column' )
+				.evaluateAll( ( cols ) =>
+					cols.map( ( c ) => c.getAttribute( 'aria-label' ) )
+				);
+
+			expect( headerLabels, 'header should have 7 columns' ).toHaveLength(
+				7
+			);
+			const expectedHeader = Array.from(
+				{ length: 7 },
+				( _, i ) => WEEKDAYS[ ( startOfWeek + i ) % 7 ]
+			);
+			expect(
+				headerLabels,
+				'header columns should be rotated to start_of_week'
+			).toEqual( expectedHeader );
+
+			// --- Grid rows: each week has exactly 7 day cells. ---
+			const weekCellCounts = await page
+				.locator( '.simple-events-calendar-month__week' )
+				.evaluateAll( ( weeks ) =>
+					weeks.map(
+						( w ) =>
+							w.querySelectorAll(
+								'[data-js="simple-events-calendar-day"]'
+							).length
+					)
+				);
+			expect( weekCellCounts.length ).toBeGreaterThan( 0 );
+			for ( const count of weekCellCounts ) {
+				expect( count, 'each week should have 7 cells' ).toBe( 7 );
+			}
+
+			// --- Day cells in DOM order, each with its datetime + other-month flag. ---
+			const cells = await page
+				.locator(
+					'.simple-events-calendar-month__body [data-js="simple-events-calendar-day"]'
+				)
+				.evaluateAll( ( els ) =>
+					els.map( ( el ) => ( {
+						datetime: el
+							.querySelector( 'time' )
+							.getAttribute( 'datetime' ),
+						otherMonth: el.classList.contains(
+							'simple-events-calendar-month__day--other-month'
+						),
+					} ) )
+				);
+
+			// Whole number of weeks.
+			expect(
+				cells.length % 7,
+				'grid should be a whole number of weeks'
+			).toBe( 0 );
+
+			// First cell sits in the start_of_week column.
+			expect(
+				weekdayOf( cells[ 0 ].datetime ),
+				'first grid cell weekday should equal start_of_week'
+			).toBe( startOfWeek );
+
+			// Last cell closes the week.
+			expect(
+				weekdayOf( cells[ cells.length - 1 ].datetime ),
+				'last grid cell weekday should be start_of_week + 6'
+			).toBe( ( startOfWeek + 6 ) % 7 );
+
+			// First in-month day (the 1st of the displayed month) lands in the
+			// column predicted by the fix: (weekday - start_of_week + 7) % 7.
+			const firstInMonthIndex = cells.findIndex( ( c ) => ! c.otherMonth );
+			expect(
+				firstInMonthIndex,
+				'grid should contain in-month days'
+			).toBeGreaterThanOrEqual( 0 );
+
+			const firstInMonth = cells[ firstInMonthIndex ];
+			expect(
+				firstInMonthIndex % 7,
+				`1st of month (${ firstInMonth.datetime }) should sit in its expected column`
+			).toBe(
+				( weekdayOf( firstInMonth.datetime ) - startOfWeek + 7 ) % 7
+			);
+		} );
+	}
+} );
diff --git a/tests/phpunit/Calendar/CalendarGridTest.php b/tests/phpunit/Calendar/CalendarGridTest.php
new file mode 100644
index 0000000..6271eaa
--- /dev/null
+++ b/tests/phpunit/Calendar/CalendarGridTest.php
@@ -0,0 +1,173 @@
+<?php
+/**
+ * Tests for the calendar month grid aligning to the WordPress start_of_week.
+ *
+ * Regression coverage for the day-of-week fix (PR #76): the month grid must
+ * line up under the correct weekday columns for every start_of_week value
+ * (0 = Sunday through 6 = Saturday), not just Monday.
+ *
+ * @package Simple_Events
+ */
+class CalendarGridTest extends WP_UnitTestCase {
+
+	/**
+	 * Restore the start_of_week option after each test.
+	 *
+	 * @var mixed
+	 */
+	private $original_start_of_week;
+
+	/**
+	 * Stash the original option before each test.
+	 *
+	 * @return void
+	 */
+	public function set_up() {
+		parent::set_up();
+		$this->original_start_of_week = get_option( 'start_of_week' );
+	}
+
+	/**
+	 * Restore the original option after each test.
+	 *
+	 * @return void
+	 */
+	public function tear_down() {
+		update_option( 'start_of_week', $this->original_start_of_week );
+		parent::tear_down();
+	}
+
+	/**
+	 * For every start_of_week (0-6) the grid must:
+	 *   - start on a cell whose weekday equals start_of_week,
+	 *   - end on a cell whose weekday equals start_of_week + 6 (mod 7),
+	 *   - contain a whole number of 7-day weeks.
+	 *
+	 * Checked across several months whose first day falls on different
+	 * weekdays so the offset maths is exercised from every starting position.
+	 *
+	 * @return void
+	 */
+	public function test_grid_aligns_to_start_of_week_for_all_values() {
+		$months = array(
+			'2026-02-01', // Sun
+			'2026-03-01', // Sun
+			'2026-05-01', // Fri
+			'2026-06-01', // Mon
+			'2026-08-01', // Sat
+			'2026-09-01', // Tue
+			'2026-10-01', // Thu
+		);
+
+		for ( $start_of_week = 0; $start_of_week <= 6; $start_of_week++ ) {
+			update_option( 'start_of_week', $start_of_week );
+
+			foreach ( $months as $month ) {
+				$days = SE_Calendar::get_instance()->get_month_days( $month )['days'];
+
+				$context = sprintf( 'start_of_week=%d month=%s', $start_of_week, $month );
+
+				// Whole weeks only.
+				$this->assertSame(
+					0,
+					count( $days ) % 7,
+					"Grid should be a whole number of weeks ({$context})."
+				);
+
+				// First cell sits in the start_of_week column.
+				$first_weekday = (int) $days[0]['date']->format( 'w' );
+				$this->assertSame(
+					$start_of_week,
+					$first_weekday,
+					"First grid cell weekday should equal start_of_week ({$context})."
+				);
+
+				// Last cell closes the week.
+				$last_weekday = (int) end( $days )['date']->format( 'w' );
+				$this->assertSame(
+					( $start_of_week + 6 ) % 7,
+					$last_weekday,
+					"Last grid cell weekday should be start_of_week + 6 ({$context})."
+				);
+			}
+		}
+	}
+
+	/**
+	 * The grid must contain every day of the target month exactly once, with
+	 * leading/trailing cells flagged as is_other_month.
+	 *
+	 * @return void
+	 */
+	public function test_grid_contains_every_day_of_the_month() {
+		update_option( 'start_of_week', 1 );
+
+		$month         = '2026-06-01';
+		$days          = SE_Calendar::get_instance()->get_month_days( $month )['days'];
+		$days_in_month = (int) ( new DateTime( $month ) )->format( 't' );
+
+		$in_month = array();
+		foreach ( $days as $day ) {
+			if ( ! $day['is_other_month'] ) {
+				$in_month[] = $day['date']->format( 'Y-m-d' );
+			}
+		}
+
+		// Every calendar date June 1-30 present, in order, no gaps or repeats.
+		$expected = array();
+		for ( $d = 1; $d <= $days_in_month; $d++ ) {
+			$expected[] = sprintf( '2026-06-%02d', $d );
+		}
+
+		$this->assertSame( $expected, $in_month, 'Grid should list each day of the month once, in order.' );
+	}
+
+	/**
+	 * The 1st of the month must render in the column predicted by the same
+	 * modular offset used by the fix: ( firstWeekday - start_of_week + 7 ) % 7.
+	 *
+	 * @return void
+	 */
+	public function test_first_of_month_lands_in_correct_column() {
+		$month         = '2026-08-01'; // 1 Aug 2026 is a Saturday (w = 6).
+		$first_weekday = 6;
+
+		for ( $start_of_week = 0; $start_of_week <= 6; $start_of_week++ ) {
+			update_option( 'start_of_week', $start_of_week );
+
+			$days = SE_Calendar::get_instance()->get_month_days( $month )['days'];
+
+			$column = null;
+			foreach ( $days as $index => $day ) {
+				if ( '2026-08-01' === $day['date']->format( 'Y-m-d' ) ) {
+					$column = $index % 7;
+					break;
+				}
+			}
+
+			$this->assertNotNull( $column, "1 Aug 2026 should appear in the grid (start_of_week={$start_of_week})." );
+			$this->assertSame(
+				( $first_weekday - $start_of_week + 7 ) % 7,
+				$column,
+				"1 Aug 2026 should sit in the expected column (start_of_week={$start_of_week})."
+			);
+		}
+	}
+
+	/**
+	 * The Sunday-start regression: with start_of_week = 0 a month whose 1st is
+	 * a Sunday must begin the grid on that 1st (no leading padding from the
+	 * previous month). The pre-fix Monday-only maths pushed it a row down.
+	 *
+	 * @return void
+	 */
+	public function test_sunday_start_with_first_day_on_sunday_has_no_leading_padding() {
+		update_option( 'start_of_week', 0 );
+
+		// 1 Mar 2026 is a Sunday.
+		$days = SE_Calendar::get_instance()->get_month_days( '2026-03-01' )['days'];
+
+		$this->assertSame( '2026-03-01', $days[0]['date']->format( 'Y-m-d' ), 'Grid should open on 1 Mar 2026 with no padding.' );
+		$this->assertFalse( $days[0]['is_other_month'], 'First cell should belong to the target month.' );
+	}
+}