The shorter release date is exactly what is supposed to happen, and it is good news rather than a mistake.
When a sentence is imposed and the inmate enters the system, good time credits are applied at the start of the sentence rather than earned gradually over time. In California, most inmates receive a standard credit of half time, meaning they serve approximately 50 percent of the imposed sentence for most offenses, though some charges carry different percentages. On a three year sentence, that calculation brings the actual time served down to significantly less than three years, and the projected release date reflects that reduction already built in.
The move from Adelanto to West Valley Detention Center, both of which are San Bernardino County facilities, is a routine transfer within the same county system. That kind of movement between facilities in the same jurisdiction does not affect the sentence calculation or the release date.
What can change the release date is conduct going forward. Good time credits are applied upfront but can be taken away through disciplinary infractions. Every write-up he receives between now and March 23, 2020 is a potential threat to that date. A clean disciplinary record from this point forward protects the credits already applied and keeps the release date where it is. Getting into trouble, picking up infractions, or having good time stripped for any reason pushes that date further out.
The March 2020 date is real and achievable. Keeping it requires nothing more complicated than following the rules and giving staff no reason to take anything away.