Add publish_date and expiry_date support

app/content.php

@@ -120,7 +120,10 @@ function buildNavigation(Context $ctx): array {
         
         $itemPath = "{$ctx->contentDir}/$item";
         $metadata = loadMetadata($itemPath);
-        
+
+        // Skip invisible content (future publish or expired)
+        if (!isVisible($metadata)) continue;
+
         // Only include if explicitly marked as menu item
         // parse_ini_file returns boolean true as 1, false as empty string, and "true"/"false" as strings
         if (!$metadata || !isset($metadata['menu']) || !$metadata['menu']) {

app/helpers.php

@@ -1,5 +1,15 @@
 <?php
 
+// Check if content is visible based on publish_date and expiry_date
+// No metadata or absent fields = always visible
+function isVisible(?array $metadata): bool {
+    if (!$metadata) return true;
+    $today = gmdate('Y-m-d');
+    if (isset($metadata['publish_date']) && $today < $metadata['publish_date']) return false;
+    if (isset($metadata['expiry_date'])  && $today > $metadata['expiry_date'])  return false;
+    return true;
+}
+
 function resolveTemplate(string $templateName): string {
     $customTemplate = dirname(__DIR__) . "/custom/templates/$templateName.php";
     $defaultTemplate = __DIR__ . "/default/templates/$templateName.php";
@@ -39,6 +49,9 @@ function buildListItems(string $dir, Context $ctx, ?array $parentMetadata): arra
     $items = array_filter(array_map(function($item) use ($dir, $ctx) {
         $itemPath = "$dir/$item";
         $metadata = loadMetadata($itemPath);
+
+        if (!isVisible($metadata)) return null;
+
         $coverImage = findCoverImage($itemPath);
         $pdfFile = findPdfFile($itemPath);
 

app/router.php

@@ -194,6 +194,13 @@ switch ($parsedPath['type']) {
             exit;
         }
         
+        $metadata = loadMetadata($dir);
+        if (!isVisible($metadata)) {
+            http_response_code(404);
+            renderTemplate($ctx, "<h1>404 - Page Not Found</h1><p>The requested page could not be found.</p>", 404);
+            exit;
+        }
+        
         $contentFiles = findAllContentFiles($dir);
         if (!empty($contentFiles)) {
             renderMultipleFiles($ctx, $contentFiles, $dir);
@@ -218,7 +225,13 @@ switch ($parsedPath['type']) {
 
         // Load metadata for this directory
         $metadata = loadMetadata($dir);
-        
+    
+        if (!isVisible($metadata)) {
+            http_response_code(404);
+            renderTemplate($ctx, "<h1>404 - Page Not Found</h1><p>The requested page could not be found.</p>", 404);
+            exit;
+        }
+
         // Check if hide_list is enabled - if so, treat as page
         if (isset($metadata['hide_list']) && $metadata['hide_list']) {
             if (!empty($contentFiles)) {

devel/tests/helpers/is_visible.phpt

@@ -0,0 +1,21 @@
+--TEST--
+isVisible: returns true when metadata is null or date fields absent
+--FILE--
+<?php
+require '/var/www/app/hooks.php';
+require '/var/www/app/context.php';
+require '/var/www/app/helpers.php';
+
+// Null metadata = always visible
+echo isVisible(null) ? "true\n" : "false\n";
+
+// Empty array = always visible
+echo isVisible([]) ? "true\n" : "false\n";
+
+// Metadata without date fields = always visible
+echo isVisible(['title' => 'Hello']) ? "true\n" : "false\n";
+?>
+--EXPECT--
+true
+true
+true

devel/tests/helpers/is_visible_dates.phpt

@@ -0,0 +1,60 @@
+--TEST--
+isVisible: enforces publish_date and expiry_date boundaries
+--FILE--
+<?php
+require '/var/www/app/hooks.php';
+require '/var/www/app/context.php';
+require '/var/www/app/helpers.php';
+
+$today = gmdate('Y-m-d');
+
+// Helper to create tomorrow/yesterday dates
+$tomorrow = gmdate('Y-m-d', strtotime('+1 day'));
+$yesterday = gmdate('Y-m-d', strtotime('-1 day'));
+
+// Future publish_date = hidden
+echo isVisible(['publish_date' => $tomorrow]) ? "visible\n" : "hidden\n";
+
+// Past publish_date = visible
+echo isVisible(['publish_date' => $yesterday]) ? "visible\n" : "hidden\n";
+
+// Publish date = today = visible (inclusive)
+echo isVisible(['publish_date' => $today]) ? "visible\n" : "hidden\n";
+
+// Past expiry_date = hidden
+echo isVisible(['expiry_date' => $yesterday]) ? "visible\n" : "hidden\n";
+
+// Future expiry_date = visible
+echo isVisible(['expiry_date' => $tomorrow]) ? "visible\n" : "hidden\n";
+
+// Expiry date = today = visible (inclusive)
+echo isVisible(['expiry_date' => $today]) ? "visible\n" : "hidden\n";
+
+// Both set, today in range = visible
+echo isVisible([
+    'publish_date' => $yesterday,
+    'expiry_date'  => $tomorrow,
+]) ? "visible\n" : "hidden\n";
+
+// Both set, today before range = hidden
+echo isVisible([
+    'publish_date' => $tomorrow,
+    'expiry_date'  => gmdate('Y-m-d', strtotime('+2 days')),
+]) ? "visible\n" : "hidden\n";
+
+// Both set, today after range = hidden
+echo isVisible([
+    'publish_date' => gmdate('Y-m-d', strtotime('-3 days')),
+    'expiry_date'  => $yesterday,
+]) ? "visible\n" : "hidden\n";
+?>
+--EXPECT--
+hidden
+visible
+visible
+hidden
+visible
+visible
+visible
+hidden
+hidden

docs/04-development/02-content-system.md

@@ -55,9 +55,44 @@ Returns flat key-value array with a special `_raw` key containing the full parse
 | `redirect` | string | — | External URL (list items can redirect) |
 | `feed` | bool | `false` | Enable Atom feed on list pages (`feed.xml`) |
 | `author` | string | title | Atom feed author name (falls back to page title) |
+| `publish_date` | string (YYYY-MM-DD) | — | Earliest date content is visible |
+| `expiry_date` | string (YYYY-MM-DD) | — | Last date content is visible (inclusive) |
 | `plugins` | string | — | Comma-separated page-level plugin names |
 
-### Settings Section
+## Visibility (Scheduling)
+
+Content can be scheduled using `publish_date` and `expiry_date`. Both fields are optional — when absent, content is always visible.
+
+When set:
+- **`publish_date`** — Content becomes visible on this date (inclusive). Before this date it is treated as non-existent.
+- **`expiry_date`** — Content remains visible through this date (inclusive). After this date it is treated as non-existent.
+
+Invisible content is:
+- Hidden from list views (`buildListItems()`)
+- Excluded from navigation (`buildNavigation()`)
+- Returns 404 on direct access (page and list cases in `router.php`)
+- Omitted from Atom feeds automatically (feeds use the filtered items array)
+
+The check uses UTC (`gmdate('Y-m-d')`) so behavior is consistent regardless of server timezone.
+
+These fields can be overridden per-language in `[en]` sections via the language plugin:
+
+```ini
+title = "Event"
+publish_date = "2025-10-01"
+expiry_date  = "2025-10-07"
+
+[no]
+title = "Arrangement"
+publish_date = "2025-10-01"
+expiry_date  = "2025-10-08"
+```
+
+### `isVisible(?array $metadata): bool`
+
+Pure function in `helpers.php`. Returns `true` when content should be visible, `false` otherwise. Accepts nullable metadata — returns `true` for `null` (no metadata file = always visible).
+
+## Settings Section
 
 ```ini
 [settings]