Update monitor.py

Author: infwinston

fastchat/serve/monitor/monitor.py

@@ -438,7 +438,7 @@ def build_arena_tab(
 
     arena_dfs = {}
     category_elo_results = {}
-    last_updated_time = elo_results["full"]["last_updated_datetime"].split(" ")[0]
+    last_updated_time = str(elo_results["full"]["last_updated_datetime"]).split(" ")[0]
 
     for k in key_to_category_name.keys():
         if k not in elo_results:
@@ -964,9 +964,9 @@ def build_leaderboard_tab(
                     </div>
                     """,
                 )
-                last_updated_time = elo_results_text["full"][
+                last_updated_time = str(elo_results_text["full"][
                     "last_updated_datetime"
-                ].split(" ")[0]
+                ]).split(" ")[0]
                 gr.Markdown(
                     make_arena_leaderboard_md(
                         elo_results_text["full"]["leaderboard_table_df"],