My FiancŽ is in Jail right now being held on a detainer. He is on probation for a previous DUI charge and has new simple assault charges brought upon him which is going to trial. Is he going to be violated at the violation hearing and if so how much time will he have to do? He has already been in for a month. Will time be served?

It is up to the judge, was drinking involved in the new crime? If it was, the judge may look at it even more serious.
The thing is that you never know what a judge may do? He could be sentenced to jail for his entire probation sentence, or released back to probation.

See, the new charge is simple assault, but the police are trying to say there is a DUI pending charge that the blood work is not back yet for.He blew into there alcohol thingy 3 times and they couldn't get anything on him. Also he wasn't driving so Im not sure why the made him do a sobority test or blood work. He already had the prelim. Hearing for the simple assault and that is going to trial cause really he was defending himself from being injured and pushed the man back away from him and they are calling that simple assault cause the man fell down and twisted his ankle and hurt his back and head in the fall.

OK, will his drinking be part of the reason for the assault?
You say he had to blow in, that would be if they were thinking about charging him perhaps with public drunk.

Also if he was drinking or at a bar, that will be another issue for probation since that alone will be another violation of the DUI. So did they want to make him blow when he was arrested for the assault?

Also if he was in a parked car but was in the drivers seat, and had the keys, in some states that is enough to get another DUI.

So if he has more charges pending, that can change everything in court.

Drinking was not the reason for assault but I guess the victim was trying to say it was but my fiance's lawyer asked him if he saw him drinking and the man said no I just assume. But after my fiancé pushed the man we left. The cops pulled us over and said the had reason to believe my fiancé was driving, which when we pulled over I was in the drivers seat so that was weird to begin with. They gave him the passenger a sobrity test and the blow thing then took him to the hospital for blood work. How long does it take for blood work to come back. How long do they have to file this new charge if they do try and charge him with another DUI?