nope, may-day is a regional holiday in Switzerland. The following cantons don't get a day (or several days) off:

Aargau
Appenzell (both)
Bern
Geneva
Glarus
Graubünden
Luzern
Neuchâtel
Nidwalden
Obwalden
Schwiiz
St. Gallen
Uri
Vaud
Wallis
Zug

that's usually because they have other public holidays that the rest of the Cantons don't have. In Aargau, "Berchtoldstag" is a holiday, for example.

Many other European countries don't consider may-day a holdiay. The UK, for example, but also Austria, Denmark and the Netherlands.

regards,

dakis