The countdown starts on the USB end (on the right in the photo), so it's dry for 18 minutes and will start raining in 20 minutes. It'll rain for about 34 minutes, and then dry for over an hour.
I did eventually figure that one out via deduction, but thanks for the offer none-the-less.
But I will share a bit for any other noob (like myself) that finds this helpful.
I came up with a solution that could certainly be tidier, but it worked an…