Tidman comes to Edgeley Park
The 24-year-old had a previous trial last August with the Edgeley Park side as well as another trial at Bradford City earlier this month.
Should Tidman receive his international clearance in time from Belgian club La Louviere, the Scandinavian could make his County debut in the Division Two clash at Bristol City on Saturday.
Having negotiated his release from the Belgian club, Tidman will have until the end of the season to show player-manager Carlton Palmer that he is worth the award of a long-term contract for the next campaign.
The former Malmo and Gent custodian told the club's official website last August of his desire to play in English football.
Tidman said: "It's every player's dream to play in England and I am no exception."