Format date column to show only date, not time

- Add format_date_column function to leaderboard_transformer.py
- Apply date formatting in ui_components.py for all table displays
- Strips time portion from ISO datetime strings (e.g. 2025-11-24T19:56:00 -> 2025-11-24)

leaderboard_transformer.py

@@ -1360,6 +1360,42 @@ def format_runtime_column(df: pd.DataFrame, runtime_col_name: str) -> pd.DataFra
     return df
 
 
+def format_date_column(df: pd.DataFrame, date_col_name: str = "Date") -> pd.DataFrame:
+    """
+    Formats a date column to show only the date part (YYYY-MM-DD), removing the time.
+    
+    Args:
+        df: The DataFrame to modify.
+        date_col_name: The name of the date column to format (default: "Date").
+    
+    Returns:
+        The DataFrame with the formatted date column.
+    """
+    if date_col_name not in df.columns:
+        return df  # Return the DataFrame unmodified if the column doesn't exist
+    
+    def apply_date_formatting(date_value):
+        if pd.isna(date_value) or date_value == '':
+            return ''
+        
+        # Handle ISO format strings like "2025-11-24T19:56:00.092865"
+        if isinstance(date_value, str):
+            # Extract just the date part (before the 'T')
+            if 'T' in date_value:
+                return date_value.split('T')[0]
+            # If it's already in date format, return as-is
+            return date_value[:10] if len(date_value) >= 10 else date_value
+        
+        # Handle pandas Timestamp or datetime objects
+        try:
+            return pd.to_datetime(date_value).strftime('%Y-%m-%d')
+        except (ValueError, TypeError):
+            return str(date_value)
+    
+    df[date_col_name] = df[date_col_name].apply(apply_date_formatting)
+    return df
+
+
 def get_pareto_df(data, cost_col=None, score_col=None):
     """
     Calculate the Pareto frontier for the given data.

ui_components.py

@@ -19,6 +19,7 @@ from leaderboard_transformer import (
     format_cost_column,
     format_score_column,
     format_runtime_column,
+    format_date_column,
     get_pareto_df,
     clean_llm_base_list,
     get_company_from_model,
@@ -600,6 +601,10 @@ def create_leaderboard_display(
             if "Runtime" in col:
                 df_display = format_runtime_column(df_display, col)
         
+        # Format Date column to show only date (not time)
+        if "Date" in df_display.columns:
+            df_display = format_date_column(df_display, "Date")
+        
         # Clean the Language Model column first
         df_display['Language Model'] = df_display['Language Model'].apply(clean_llm_base_list)
         
@@ -1188,6 +1193,10 @@ def create_benchmark_details_display(
         if benchmark_runtime_col in benchmark_table_df.columns:
             benchmark_table_df = format_runtime_column(benchmark_table_df, benchmark_runtime_col)
         
+        # Format Date column to show only date (not time)
+        if "Date" in benchmark_table_df.columns:
+            benchmark_table_df = format_date_column(benchmark_table_df, "Date")
+        
         # Rename columns for a cleaner table display, as requested
         benchmark_table_df.rename(columns={
             benchmark_score_col: 'Score',