A good-after-time (GAT) order is a trading instruction which can be combined with market orders, limit orders and other order types. A GAT order instructs a broker to wait until a predetermined time or date has transpired before placing the order.
Example of a good-after-time instruction:
You want to sell 10,000 shares in a company’s stock. However, you only want to sell the shares after their ex-dividend date, because you want to benefit from dividend distributions. You place a market order with your broker instructing them to sell your shares at the highest available bids. You add a GAT instruction which informs your broker that the shares are not to be sold until the date immediately proceeding the ex-dividend date. The broker will only offer your shares on a stock exchange on the date you specify in the GAT instruction.