diff --git a/deploy/server.mjs b/deploy/server.mjs
index 4e00bbd..69c1d69 100644
--- a/deploy/server.mjs
+++ b/deploy/server.mjs
@@ -10,6 +10,13 @@ const port = Number(process.env.APP_PORT || 3200);
 const dataDirectory = process.env.DATA_DIR || join(process.cwd(), "data");
 const usageLogPath = join(dataDirectory, "usage.jsonl");
 mkdirSync(dataDirectory, { recursive: true });
+
+function formatChinaTimestamp(date) {
+  return new Date(date.getTime() + 8 * 60 * 60 * 1000)
+    .toISOString()
+    .replace("Z", "+08:00");
+}
+
 const mimeTypes = {
   ".css": "text/css; charset=utf-8",
   ".html": "text/html; charset=utf-8",
@@ -41,8 +48,10 @@ function writeUsageLog(request, response) {
         sendJson(response, 400, { error: "Invalid event" });
         return;
       }
+      const now = new Date();
       const entry = {
-        timestamp: new Date().toISOString(),
+        timestamp: now.toISOString(),
+        timestamp_cn: formatChinaTimestamp(now),
         event: input.event,
         client_hash: request.headers["x-forwarded-for"] || request.socket.remoteAddress
           ? createHash("sha256").update(String(request.headers["x-forwarded-for"] || request.socket.remoteAddress)).digest("hex").slice(0, 16)