Historical tick data

Alpaca Market Data
1

I’m trying to extract tick trade data, it begins 4:00:00 (pre market) but ends just before 16:00.
I can’t understand why it includes after hours trades?
Can anyone help me?
My code is below.
def collect_and_store_data(symbol, target_date, client, conn):
ny_tz = pytz.timezone(‘America/New_York’)
start_of_day_naive = datetime(target_date.year, target_date.month, target_date.day)
base_dt = ny_tz.localize(start_of_day_naive)

total_inserted_count = 0
cursor = conn.cursor()
try:
    for i in range(96):
        start_dt_aware = base_dt + timedelta(minutes=i * 15)
        end_dt_aware = base_dt + timedelta(minutes=(i + 1) * 15) - timedelta(microseconds=1)
        request_params = StockTradesRequest(
            symbol_or_symbols=symbol,
            start=start_dt_aware,
            end=end_dt_aware
        )
        trades_response = client.get_stock_trades(request_params)

        if symbol in trades_response.data and trades_response.data[symbol]:
            trade_list = trades_response.data[symbol]
            trade_data_to_insert = [
                (t.timestamp, t.symbol, t.price, t.size, t.exchange, t.conditions, t.tape)
                for t in trade_list
            ]
            
            sql = """
            INSERT INTO trades (time, symbol, price, size, exchange, conditions, tape)
            VALUES %s ON CONFLICT DO NOTHING;
            """
            execute_values(cursor, sql, trade_data_to_insert)
            
            inserted_count = len(trade_data_to_insert)
            total_inserted_count += inserted_count
            print(f" {inserted_count}trades counted")
        else:
            print(f" no data ")
    conn.commit()
    print(f"  :+1: 合計 {total_inserted_count} trades commited")

except Exception as e:
    print(f"\n  :x: {symbol} error occurred roll back: {e}", file=sys.stderr)
    conn.rollback()
finally:
    cursor.close()