Labor Day is celebrated in France in May...

People in many areas give bouquets of lily-of-the-valley or dog rose flowers to loved ones. This custom is particularly common in the area around Paris known as Île-de-France. Families with children in country areas get up early in the morning and go into the woods to pick the flowers. Individuals and labor organizations in urban areas sell bouquets of lily of the valley on the street on May 1. There are special regulations that allow people and some organizations to sell these flowers on May 1 without paying tax or complying with retail regulations. Trade unions and other organizations organize parades and demonstrations to campaign for workers rights on May 1. People may also use these events to campaign for human rights in general, to demonstrate against racism or highlight current social issues. May 1 is a public holiday. Post offices, banks, stores and other businesses are closed. Outside of tourist areas, restaurants and cafes may be closed. However, some stores in Paris, as well as at airports and railway stations and along major highways, may be open. Public transport service schedules vary depending on where one lives and intends to travel. Parades and demonstrations may cause disruption to traffic in the centers of large cities, particularly Paris. 

King Charles IX of France was presented with lily of the valley flowers on May 1, 1561. He liked the gift and decided to present lily of the valley flowers to the ladies of his court each year on May 1. Around 1900, men started to present a bouquet of lily of the valley flowers to women to express their affection. The flowers are a more general token of appreciation between close friends and family members these days.