Organisers of a nationwide protest against salary discrimination towards women expect up to 100,000 participants on June 14.
They say women still earn about 20 per cent less than men despite a no discrimination clause in the constitution.
More than 40 groups - including the association of women’s organisations and the trade unions, representing more than a million people – are taking part in activities across the country, notably a concerted whistle call.
To mark the day, the water in the giant jet d’eau fountain in Geneva will be violet – an official colour of the protest movement, while demonstrations are planned in shopping malls in Basel.
A public party for women has been organised in Bern while women in Lugano will hang out dirty laundry in the streets.
The events coincide with a mass protest 20 years known as the women’s strike.
Swiss women only obtained full political rights allowing them to participate in nationwide ballots 40 years ago.
swissinfo.ch and agencies