I think part of the problem with your original syntax is the GETVAL(). It's not needed.
Being bored, I took a slightly different approach and created an action entry rather than a shapedata entry. All you do is right click shape, then just click on the "Update Time", and current time value is applied. The formula is: SETF(GetRef(User.MyTime),NOW())+DEPENDSON(Actions.NowTime).
This approach only requires two entries: 1) User.MyTime to hold the time value, and 2) Actions.NowTime to invoke the time updating.
See attached.
It was fun to goof around.
Wapperdude