If your bf's crime occurred under the current version of PC 4019, then he will get half-time credits for his county time awaiting state prison as long as he has not committed a violent or serious felony and is not an SVP. I hope your bf is not the same man who is serving the six year sentence at 85% in the previous question because that would mean he would only get 15% credits for his county jail time (plus actual time).
Of course, the best way to answer this is to ask his lawyer who will know exactly what he was convicted of and the circumstances of his pretrial detention. For instance, certain offenses do not qualify for half time credit and, if he was in custody on another offense, he will not get credit.
The CDCR will calculate his release date upon arrival at the Reception Center. If it does not seem correct, his lawyer can request a recalculation or return the matter to court for correction.