An order that uses the good after time/date field is held in the IBKR system and submitted to the market on the date and time you specify.
Classic TWS
To place a GAT order, first add the Start Time column to your Classic TWS page. Right click on the tab/page header and select Layout. Here you will find all columns that are available to add to your TWS page. Click the Order Columns tab and find the Time in Force section. Click Start Time followed by the Add button in the middle. You should now see this column on the left side under Shown Columns. Once finished, click the Apply and OK buttons at the bottom of the window.
Once you have added the columns, bring up an order line for the instrument you wish to trade. Click the calendar icon in the Start Time field to choose a start date and time, and click OK. You can now proceed to configure the rest of your order and transmit when ready.
Mosaic
To submit GAT orders from the Mosaic layout, right-click on a ticker row from your watchlist and select Trade followed by Order Ticket. You can configure the order's Start Time in the Order Ticket.
Additional Information
- Good-After-Date/Time (GAT) orders page on the IBKR website.