Update app.py

app.py

@@ -1669,7 +1669,7 @@ def leaderboard_page():
         st.warning("Old leaderboard data detected. Play new games to enable weekly/monthly stats.")
         return
 
-    df["timestamp"] = pd.to_datetime(df["timestamp"], errors="coerce")
+    df["timestamp"] = pd.to_datetime(df["timestamp"], errors="coerce", utc=True)
     df = df.dropna(subset=["timestamp"])
 
     if df.empty:
@@ -1687,11 +1687,11 @@ def leaderboard_page():
     now = datetime.now()
 
     if filter_type == "This Week":
-        start_week = now - pd.Timedelta(days=now.weekday())
+        start_week = datetime.now(UTC) - timedelta(days=7)
         df = df[df["timestamp"] >= start_week]
 
     elif filter_type == "This Month":
-        start_month = now.replace(day=1)
+        start_month = datetime.now(UTC).replace(day=1)
         df = df[df["timestamp"] >= start_month]
 
     if df.empty: