The 45 days is probably not going to earn any good time. That 45 days starts from the minute he was picked up, regardless of where he is or will be held.
https://www.inmateaid.com/ask-the-inmate/my-boyfriend-is-currently-in-a-county-jail-he-was-told-by-his-parole-officer#answer
Accepted Answer Date Created: September 06,2016