My boyfriend is on probation for a year he has two months left... his probation officer revoked his case and is now in jail how much time will he serve

Why did the PO revoke his probation, that will determine how much time he will serve ( if any)

He will stay in jail till the hearing, which can be a couple week to almost a month at times.

If he had a dirty urine or if he missed a meeting, they may just put him back on probation, if he stole a car, they most likely put him in for the entire year ( plus sentence for new crime)