Try and come up with a believable story. Go to the doctor and tell him you were sick that day and you need a note. If you miss for a medical reason, they probally will let it go the first time. Livonia is fucked up when it comes to shit like that, so if he doesn't come up with a good excuse, they might make him do a couple days and still finish probation. Honestly my advice is to say fuck your probation and do the time. If its from simple posession, he'll probally end up serving 2 weeks, maybe less. I said fuck the probation in Farmington Hills and it was a holiday weekend when i got picked up so I did 4 days at OCJ before court and I ended up getting sentenced to the 4 days of time served (no more probation). 4 days OCJ or a year of piss tests....who wouldn't take the 4 days....I'm not saying everyone gets 4 days....I think they also took into consideration the fact that I had become a legal patient since my arrest and that my probation costs were already paid. All they care about is your money. If you can't afford there costs, they throw you in jail just long enough to teach you a lesson, then they bill you for your jail time. Not too many educated people honestly believe that pot is wrong.