City Hall is normally a sleepy place at midnight, but not on one day in August this year.
The city says it will open the building for marriages at 12:01 a.m. on the first day licenses can be issued to same-sex partners.
The law will go into effect on August 1, but the first weddings may not occur for several days because of a license waiting period. The city's statement about the occassion left the date unclear.
Mayor R.T. Rybak will even be there to officiate weddings, the city said in a statement.
The building is run by a joint board of the city and the county, known as the Municipal Building Commission.
NOTE: This post originally said the weddings would occur at 12:01 on August 1. It has been updated to reflect the fact that the exact date remains unclear right now because of license waiting periods.