August 1st is to the Swiss what July 4th is to Americans, or July 14th to the French. Swiss national day is only just over a century old, and it was only in 1993 that the hardworking Swiss agreed that they could all take the day off, but the event it commemorates took place 700 years ago, and at the heart of the celebrations is a custom which doubtless goes back into the mists of time.
The day was chosen because August 1st 1291 was the date on which three Alpine cantons swore the oath of confederation, an act which later came to be regarded as the foundation of Switzerland. The representatives of Schwyz, Unterwalden and Uri met on the Rütli field, high above Lake Lucerne, to swear a bond of brotherhood, and agree to act jointly if their freedoms were threatened by outside aggressors.
So it's not surprising that the official part of the August 1st celebrations take place on the Rütli even today, with a public gathering addressed by the Federal president. Indeed, it's a day for speeches, with politicians at all levels, from Federal councillors to the heads of communes, addressing meetings all over Switzerland.
For most people, August 1st means bonfires and fireworks and barbecues in the garden or brunch on the farm.
Long before the government decided in 1891 to declare the day Switzerland's national day, people had celebrated summer by lighting bonfires. Indeed, the custom of lighting a fire on June 24th, St John's Day, is known all over Europe. But for the Swiss, bonfires had an extra significance. For centuries they had built beacons on mountain tops which they lit when danger approached. One legend told of both Lake Geneva and Lake Biel relates how hordes of invading barbarians intent on conquering the ancient Swiss tribes turned back when they saw the lights reflected in the lake waters, thinking they had come to the edge of the earth and were about to ride off into the sky.
Whether in remembrance of this event, or just because it is fun, every Swiss commune now lights its own bonfire and sets off fireworks, and children parade through the streets with paper lanterns - often decorated with the Swiss cross or the symbols of the cantons - and people light candles in their windows.
And since no celebration is complete without a feast, many people mark this festival of fire by cooking sausages over a barbecue and enjoying them with friends.
But in recent years an alternative feast has been gaining in popularity: brunch on the farm. The idea was launched in 1993, as an initiative by the Swiss Farmers' Association. Visitors are served fresh farm produce and get to see something of farmers' lives. In 2005 about 430 farms took part, serving brunch to about 200,000 people.