How long can you be held in jail for a crime that is based on hearsay, no witnesses that seen you commit said crime

You should contact an attorney immediately. In Idaho, there is a requirement to go before a Magistrate Judge within a very short period of time. Even four days is too long before initial presentment. If it has already gone before a Magistrate Judge for the initial presentment, then bail should have been set and a preliminary hearing scheduled. The preliminary hearing is where the government must convince the Magistrate there is probable cause to believe a crime has been committed and the person in custody committed it.

Get a lawyer right away. Please do not discuss his situation online, or even privately with anyone. This Q&A forum is not confidential. He has some defenses but all this should be discuss in a confidential setting.