The Taiwan Financial Supervisory Commission is considering to adjust the trading time of the Taiwan Stock Market. This plan has provoked a great deal of controversy especially for stockbrokers and foreign investors. Therefore, the purpose of this article is to build a theoretical model to analyze the effects of extending the trading time on investors' order submission strategies in a dynamic order-driven market. The model shows that extending trading time will increase the probability of order execution, and as a result, liquidity traders will more likely place limit orders. The model shows that no matter how long the trading time is, informed traders' best strategy is to place limit orders. These results indicate that extending the trading time can increase the liquidity of the order-driven market, and hence we corroborate the viewpoint of stockbrokers on extending the trading time.