A Target Date, as defined in INPUT-target date (described below), can be used in variable creation. When no target date has been specified yet, the default value is the current date. When dragging a literal Target Date into a variable, the following tree element is created.
Variable Creation > Input > Variables: SQL Elements pane - Literal Parameters > Target Date

A default date of today’s date is provided, but can be changed via the Properties panel. Double-click on Target Date or highlight and click Properties.
Variable Creation > Input > Variables: SQL Elements pane - Literal Parameters > Target Date Properties

Either the standard Windows Calendar control (reached by selecting the pull-down arrow of the selector) can be used to set the desired date by clicking through the months in the calendar using the < and > buttons, or the date can be set by just typing in the desired values for the month, day and year, one at a time.