The time he already spent in county counts. Every day from his August arrest date forward is credited toward his sentence, so he walked into Oakdale and then Newton with those months already on the board.
Iowa operates under a determinate sentencing structure with good time provisions. For most felony sentences, Iowa inmates are eligible to earn good time credits that can reduce the actual time served. The standard in Iowa is that inmates can earn up to 1.2 days of credit for every day served in good standing, which works out to serving roughly 70 percent of the sentence before becoming eligible for release consideration. On a five year sentence that puts the target around three and a half years, minus the time already served in county since August.
The movement from county to Oakdale to Newton is a normal part of Iowa's classification and designation process. Oakdale is the Iowa Medical and Classification Center where the state sends newly sentenced inmates for evaluation before assigning them to a permanent facility. Newton Correctional Facility is his designated permanent placement based on that classification. The moves themselves do not affect his sentence calculation.
His case manager at Newton can give him the most accurate projected release date based on his specific sentence, jail credit calculation, and good time eligibility. That conversation is worth having early so he knows exactly what timeline he is working with and what he needs to do to protect his good time credits through the remainder of his sentence.