Dyngus Day or Wet Monday (Polish Śmigus-dyngus) is the name for Easter Monday in Poland. It is a peculiar custom on this day and it is splashing everyone with cold water. Why, for centuries it was a pagan custom to clear your self and house before Spring will came, after Christianity came to Poland that custom had the same symbolic but related to clear you soul from sins. Pagan custom became a Christian custom and everybody is happy.
It is really a watery day, elderly just asperse heads with perfumes but children and teenagers are really having a fun. Mark of good fun in that day is how many times you will have to go back to home to change your ware. Yung men are driving streets hunting for some girls to splash with cold water, and everyone else. They watch to catch you near the church or after the church.
You have to go to visit someone, family, friends or just your neighbors and water splashes them. It will bring him/her good luck for whole year and naturally it is good fun for everyone. This is really happy, funny and watery day no matter is it raining.
p.s. I have not found a single photo of this custom on DT. I think it is a big opportunity for everyone.