diff --git a/backend/api/routes/trades.py b/backend/api/routes/trades.py
index 6d74a3b..193d134 100644
--- a/backend/api/routes/trades.py
+++ b/backend/api/routes/trades.py
@@ -8,6 +8,8 @@ import sys
 from pathlib import Path
 import logging
 import asyncio
+import time
+from datetime import timezone, timedelta
 
 project_root = Path(__file__).parent.parent.parent.parent
 sys.path.insert(0, str(project_root))
@@ -50,7 +52,6 @@ def get_date_range(period: Optional[str] = None):
     start_date_str = start_date.strftime('%Y-%m-%d %H:%M:%S')
     # 结束时间：使用当前时间，确保包含最新单子,北京时间
     # 使用北京时间（东八区）
-    from datetime import timezone, timedelta
     beijing_tz = timezone(timedelta(hours=8))
     end_date = datetime.now(beijing_tz)
     end_date_str = end_date.strftime('%Y-%m-%d %H:%M:%S')