If he is getting convicted on two separate felony transactions, and has the time running concurrently, he gets credit for both. If the minimums are the same, there is no difference in eligibility for parole date unless he accredited time previously on one but not the other. Best case scenario is he is eligible for parole in one year. If one of the felonies has a greater sentence than the 1-3, then the smaller one is simply eclipsed by the larger one's minimum time before parole eligibility. Shock has a list of eligibility requirements and that is determined once he is committed and the time you state alone is not a deterrent to that program. I also infer that he was not convicted of a drug charge, but placed in a diversion program because he is an addict.
If you found this "helpful" or "best answer," please click it with my appreciation. My response is for educational purposes and does not constitute legal advice nor creates an attorney client relationship which requires all the details and a personal conference.
He will get good time. 1 - 3 does not sound like a proper sentence on a felony drug case.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 577-9797 or via email at Eric@RothsteinLawNY.com. I was named to the Super Lawyers list as one of the top attorneys in New York for 2012. No more than 5 percent of the lawyers in the state are selected by Super Lawyers. The above answer is for informational purposes only and not meant as legal advice.