Changing a rewards flight

I know you can change a rewards flight as long as there is another flight available for $50 because I've already done it for my upcoming flight to London.

But, say I want to change it again (I might want more time at home). Is there a cutoff time that I must call Virgin to reschedule? 3 days before departure is coming to mind, but I can't find the fine print on their website.

Cheers,
-Matt

I think yo are after 4.2.1

And my reading is any changes need to be made 7 days in advance of the flight date