I'm not sure how you are planning on using the time stamp, but using Insert
Field to put in the current time will have the time constantly updated.
A better solution is to create a shape with a Custom property called
TimeStamp of Type 5 (date) and Format of {{HH:mm:ss}}
In the Events section for that shape set the EventDrop to
SETF("prop.TimeStamp",NOW()) to set the time when the shape is dropped.
Alternatively, you can use the same formula in the EventDblClick cell so the
time is updated each time the shape is double clicked.
Using Insert Field you can add this Custom Property to the shapes text.
John... Visio MVP