Might be of interest to people working late or finishing partying early.
The store is tiny and is a horrible place to shop, but as of yesterday the Migros in Zurich HB is open till 10pm Monday to Saturday (9pm Saturday).
www.migros.ch/DE/Regionen/Zuerich/Seiten/Zuerich.aspx
Not sure about other cities.
Cheers,
HB