Colleagues of mine have it in their contracts now that "the notice period is 30 days" i.e. you leave 30 days after giving or getting the notice, regardless of how many years you've worked their.


The trouble with the word "month" is that it's not a clear until of time like day or week. Someone new to Switzerland could easily and understandably take "one month's notice" to mean if you resign on the xth of the month you work until the xth of the next month.


One thing you can do if you have the balls is to simply tell them when you're leaving and stop working on that day.