I know exactly how you feel.
Please know that we are thinking of you and will be praying for your sweet Zach on Saturday. Will he get to come home with you that evening? I'll tell you that I have two different ways of passing time when going through these things. One is cleaning house like a mad woman.
The other is going shopping to pass the time.
Of course, your mind won't be completely on anything you do, but you can always hang out on YT to pass the time, too. We all know how you feel.