diff --git a/backend/database.js b/backend/database.js
index 1fdd5c3..7c429b9 100644
--- a/backend/database.js
+++ b/backend/database.js
@@ -682,8 +682,8 @@ const SystemLogDB = {
   log({ level = 'info', category, action, message, userId = null, username = null, ipAddress = null, userAgent = null, details = null }) {
     try {
       const stmt = db.prepare(`
-        INSERT INTO system_logs (level, category, action, message, user_id, username, ip_address, user_agent, details)
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+        INSERT INTO system_logs (level, category, action, message, user_id, username, ip_address, user_agent, details, created_at)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, datetime('now', 'localtime'))
       `);
 
       const detailsStr = details ? (typeof details === 'string' ? details : JSON.stringify(details)) : null;
@@ -776,7 +776,7 @@ const SystemLogDB = {
     return db.prepare(`
       SELECT DATE(created_at) as date, COUNT(*) as count
       FROM system_logs
-      WHERE created_at >= datetime('now', '-' || ? || ' days')
+      WHERE created_at >= datetime('now', 'localtime', '-' || ? || ' days')
       GROUP BY DATE(created_at)
       ORDER BY date DESC
     `).all(days);
@@ -786,7 +786,7 @@ const SystemLogDB = {
   cleanup(keepDays = 90) {
     const result = db.prepare(`
       DELETE FROM system_logs
-      WHERE created_at < datetime('now', '-' || ? || ' days')
+      WHERE created_at < datetime('now', 'localtime', '-' || ? || ' days')
     `).run(keepDays);
 
     return result.changes;