Update sheets.py

sheets.py

@@ -118,7 +118,10 @@ def get_sheet(tab_name: str) -> gspread.Worksheet:
 
 
 def _now() -> str:
-    return datetime.utcnow().isoformat()
+    """Returns current IST timestamp."""
+    from datetime import timezone, timedelta
+    IST = timezone(timedelta(hours=5, minutes=30))
+    return datetime.now(IST).isoformat()
 
 
 def _gen_id(prefix: str) -> str: