Wis. Stat. § 62.01: Saving clause.

That no inconvenience may arise by reason of change of government of cities from special charter to general charter, or by reason of the revision of the general charter law, it is declared that:

(1) All vested rights, pending actions and prosecutions, and existing judgments, claims, and contracts, both as to individuals and bodies corporate, shall continue as though no change had taken place.

(3) Ordinances in force, so far as not inconsistent herewith, shall continue in force until altered or repealed.

(5) Nothing herein shall change the time for paying taxes as provided in any special city charter until the council shall by ordinance change the same to conform to general law.