I thought that Duffer spoke of both clocks. And here they are:
The CC Pass clock starts when the last pass in possession is used, counting back 12 hours until the next free pass will be available. "Two in 24 hours" is a tad misleading. We may get two in 12:00:01 hours' time but we can hardly get two per day continuously.
The CDP clock starts at 12 am GMT(!), counting back for 24 hours until the next bonus day starts. See the green "?" for explanation.