The Timing Start action is used along side of a Timing End action. When the test hits the Timing Start action, it starts counting the number of seconds elapsed, and once the test hits a Timing End action, the number of seconds are then stored in the Test Resources using the Resource Key specified by the Timing End action.
Timing Start Editor
There is nothing to edit for a Timing Start action. The connection of a start to an end is handled in the Timing End action.