The Swallows Dance

The Swallows is a constellation in the night sky, interpreted as looking like two swallows in flight. The Swallows Dance is a festival in connection to this constellation. It takes place during early winter, when the swallows show the clearest in the sky. It is a one-night festival.
The Swallows Dance is, as might be inferred from the title, a dance festival. Musicians of all sorts are called upon, with stages to perform upon are built for them, and dance floors are prepared for any who wish to dance. Decorations are put up all over the city, town, village, or other settlement, white ribbons that glow in the darkness and dance with the wind. If a light snow has fallen to dust the surroundings white, and swirl underfoot with the dance, that is seen as a good sign for the next year. It is even better if a light snow starts falling during the festivities, and is seen as a good omen.
Stalls are prepared with food, decorated with swallows, either on the foodstuff itself, or the wrapping, or packaging. Clothes decorated with the bird is also sold, and one is expected to at least wear one swallow during the festival. One is also expected to dance for at least one song.
Wealthier people might arrange their own parties for the night, but it is necessary to hold it outdoors, or one is looked upon strangely. Most performers volunteer to play, though the wealthy also might pay their performers. It is seen as a great honour to be allowed to perform on any royal courts stage, as it is seen as being recognized above all other musicians.
Everyone carries dance cards for this night, and there they fill out who they will be dancing with when. Young people often compete about who has the most names on their cards. It is seen as impolite to turn down a request for a dance, though acceptable excuses do exist, such as injury or high pregnancy. One is expected to dance with a lot of different people, rather than only one, so although it could be the favourite holiday of couples, it is often not.
Still, it is a light-hearted festival meant for people to enjoy themselves and relax for a night, before the winter properly is upon them.