What's so important about June 6th?

On the sixth day of the sixth lunar month, the married daughter will go to the butcher shop to buy a knife of meat and send it back to her parents. It has been our family's practice to dry dragon clothes on June 6th. On this day, if the weather is fine, the elders will remind us to take out the clothes we don't wear to dry. Drinking mung bean soup or mung bean porridge on June 6 can ward off evil spirits and avoid prickly heat and sores.