I emailed the exact question to CO yesterday. I'll post their reply when I get it. I've got several trips planned for October and would like to book them now, though I'm willing to wait until 10/1 to "purchase" them if that's what it has to be, but it does seem silly. Everything says the credit will post after the flights are flown, which leads me to believe they're not keeping up with the actual purchase date. We shall see....