Hello Dr Galea,
The easiest way to calculate times would be to use a Counter block as an input to State Flow. You should use a 32 bit counter with the update rate set to 0.001. That will give you a relative time in milliseconds since the model started running. You would just need to grab the current time before the movement starts and when the movement ends.
Please let me know if that helps or if I can be of more assistance.
Cheers!