Originally Posted by
Dave Noble
From the Jetstar Terms and Conditions (
http://www.jetstar.com/au/en/conditions-of-carriage )
I would suggest that a 7 hour time change is definitely significant and that you should be able to cancel without penalty based on the T&Cs unless JQ can rebook you onto a flight at a similar time.
Jetstar accepted my cancellation when they changed flight by two hours. It took them 3 weeks to refund...