Sentences of less than two years are managed by the provincial correctional system. In Quebec, it's Quebec's correctional services that handle people who are sentenced to less than two years. The system operates a bit like the federal system, that is, there are day passes in preparation for parole, or PSPLCs.
To summarize, in very rare cases, it is possible to get out after one sixth of the sentence. The sentence continues, but the person gets out of prison after serving one sixth of their sentence. However, that is very rare, it is seldom applied, and it happens by decision of the CQLC, the Commission des libérations conditionnelles du Québec. Otherwise, people incarcerated for less than two years are eligible for parole at one third of their sentence. Again, the decision as to whether to grant the person parole is made by the members of the Commission des libérations conditionnelles du Québec based on the person's profile, their potential for social reintegration, and their release plan. Often, these are the people who are also going to be in a halfway house and will be monitored for the other two thirds of their sentence in the community.
There are very clear figures about this. As well, studies have shown that people who are released on parole and are supervised until the very end of their sentence reoffend less than people who get out at the equivalent of two thirds of their sentence, the point at which release is virtually mandatory at the provincial level. A person who gets out after serving the equivalent of two thirds of their sentence, for sentences of two years or less, will be released without any form of support or supervision. Those individuals reoffend more than people who get out earlier but are supervised.
In my opinion, rehabilitation involves a number of supervisory and support services and programs offered to people when they return to the community.