1 files changed, 21 insertions, 2 deletions
diff --git a/astro.config.mjs b/astro.config.mjs
index 6b6406b..6d155c5 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -8,6 +8,7 @@ import sitemap from "@astrojs/sitemap";
 import { unified } from "@astrojs/markdown-remark";
 import remarkMermaid from "remark-mermaidjs";
 import ogImagePlugin from "./src/plugins/og-image";
+import { SCHEDULE_PAGE_FILES } from "./src/data/schedule/content-files.mjs";
 import updatesIntegration from "./src/plugins/updates";
 
 // Apache (production) resolves a directory URL to its index.html, so the site can
@@ -73,13 +74,31 @@ const gitDates = buildGitDateMap();
 function lastmodFor(url) {
   const path = url.replace(/^https?:\/\/[^/]+/, "").replace(/^\/+|\/+$/g, "");
   const bases = path ? [path, `${path}/index`] : ["index"];
+  let pageDate;
   for (const base of bases) {
     for (const ext of [".mdx", ".md"]) {
       const date = gitDates.get(`src/content/docs/${base}${ext}`);
-      if (date) return new Date(date);
+      if (date) {
+        pageDate = new Date(date);
+        break;
+      }
     }
+    if (pageDate) break;
+  }
+
+  // 行事予定ページは、ページ本体だけでなく予定データ（JSON）の更新も最終更新に含める。
+  // ページ冒頭の「最終更新」と dateModified も同じ値を使っている。
+  if (path === "kodaira/events") {
+    const parts = [
+      pageDate,
+      ...SCHEDULE_PAGE_FILES.map((file) =>
+        gitDates.get(file) ? new Date(gitDates.get(file)) : undefined,
+      ),
+    ].filter(Boolean);
+    if (parts.length) return new Date(Math.max(...parts.map((d) => d.getTime())));
   }
-  return undefined;
+
+  return pageDate;
 }
 
 export default defineConfig({