One year 12 months. The term of imprisonment shall be counted from the date of criminal detention. Good behavior in it can reduce the sentence. But it depends on how long his five-year sentence is from the day he went to prison. After subtracting the first time, see if there is time to subtract the second time. You can do the math yourself. If it's too late, let's mix. But it's no trouble
Ordinary friends can't visit prison without relatives. If you want to go, there is still a way. Let his relatives bring proof (proof that they are relatives) and ID cards with them. You should also bring your ID card. What the police may ask you depends on what you say. I don't know what to ask, so I can't teach you.