There is a parking with a meter near my place, which has the operating hours between 8 am and 6 pm, Monday - Friday. My question is: how should I treat May 1st, which is Friday? Is parking free there or not?

what does it say about Feiertagen? It might be listed next to Sontag.

May 1st is considered what the Brits call a "bank holiday", so you don't have to pay.

It depends where you live. It's not a "bank holiday" in every canton and will be a normal working day in those which don't observe it.
It had only recently become a "bank holiday" in Neuchâtel and still isn't in Bern.

It's a normal working day in Geneva as well.... I've got a doctor's appointment!

It's normally accepted/tolerated here that government employees (teachers for example) take the day off.... but only if they attend the May Day march through town in the morning.

You're in luck for May 1 in Zurich. It is a holiday. Not so much in Zug.

I wouldn't leave a car parked in Zurich on May 1st...

I live in Zürich, it's in my profile, I thought you will see it .

The thing is, it does not say anything about holidays:


My friends are coming to town for 1-3.05 and I told them they will have a free parking spot, but now I am not so sure

I don't think there's a law covering this, as the basic law is that you can't park except where marked and within the rules on the sign.

Normally it's pretty clear regarding holidays, typically "Sonn- und Feiertage" so safest to assume it isn't free in this case.

Perhaps the parking officials will be having a day off.

Just my 2¢:
It should be free. But if you doubt it, just put in 50 Rappen and see what time will be displayed.

That makes a total of 52¢

That is a brilliant idea! As I don't have a car, I've never used a meter before. Thanks a million!