- 五一节 wǔyījié May DayInternational Workers' Day on May 1st
- 一五一十 yīwǔyīshí to count by fivesTo count things by fives or tens
- 五一劳动节 wǔyīláodòngjié May DayInternational Workers' Day, celebrated on May 1st to honor the labor movement and the working classes.
- 五一国际劳动节 wǔyīguójìláodòngjié International Workers' DayMay Day; a holiday celebrated on May 1st to honor the achievements of workers and the labor movement