Well, if you break curfew on the day, then I doubt anyone is going to be really fussed, and I would not be, for I would just say you add on another month, deal? But to think that you can now effectively end your sentence is another matter.
This is the problem with such arrangements. First he gets time off for the wedding night, now this, now the next. Squeaky wheels get the most grease in ball-pit Britain. Constant bleating. I wonder if certain papers who rail against multiple-appeal asylum seekers turn around and "support" this guy. Hypocrisy if they do.
This is an issue of Rule of Law. I'd rather Jack was in prison, because we are talking about an act of violence that could have resulted in death. Why is he on a tag in the first place?