Our guests Anne & Alexandra missed it as the had to return to Lausanne early. Today is an official public half-holiday and the official end of the winter. Sächseläuten is its name, or Sächsilüüte in Swiss German.
Following a parade of the Zünfte (guilds), the climax of the holiday is the burning of Winter in effigy, in the form of the Böögg, a figure of a snowman prepared with explosives.
The roots of the festival go back to medieval times when the first day of summer working hours was celebrated in the guildhalls across the city. City ordinances strictly regulated the length of the working day in that era. During the winter semester the workday in all workshops lasted as long as there was daylight, but during the summer semester (i.e. starting on Monday following vernal equinox) the law proclaimed that work must cease when the church bells tolled at six o'clock. Sechseläuten is a Swiss German word that literally translates into "The six o'clock ringing of the bells". Changing to summer working hours traditionally was a joyous occasion because it marked the beginning of the season where people had some non-working daylight hours.
Popular tradition has it that the time between the lighting of the pyre and the explosion of the Böögg`s head is indicative of the coming summer: a quick explosion promises a warm, sunny summer, a drawn-out burning a cold and rainy one. The shortest time on record is 5:07 minutes in 1974 and the longest is 43:35 minutes in... 2016.
To our summer guests: be prepared! But know as well that according to statistics, de Böögg has rarely been reliable. In 2015 the head exploded after over 20 minutes and it ended up being a very good summer.
More info on https://www.sechselaeuten.ch