The Trinity Sunday is the birthday of the Christian Church (Acts 2:1-11).
This is a day when the Holy Spirit in form of fire tongues condescended upon apostles and they began to preach about "Great Opus Dei" (Acts 2:38) in different languages. Apostle Peter declared such effusion of Spirit adumbrate as the beginning of the new messianic epoch (Acts 2:17-18). That is why the Trinity Sunday is also called the "Apocalypses day" (i.e. the day of last revelation).
The Trinity Sunday for Germans-Lutherans is traditionally related to the relations clarification between lovers. For this purpose the Maypole was set (in Germany the tree was common for all the village, and in Siberia the tree was set in front of the houses of beloved girls). The Maypole was interpreted as a symbolic form of marriage proposal. It was an ordinary tree felled in the forest with cut branches and only a green peak left. The trunk was decorated with ribbons, flags, white and red scarves. However, competitors or simply local hellions could steal the Maypole already set, so the right to set the tree had to be proved by fighting. That is why the tree was embedded deeper and in many cases it was strengthened with heavy chains.
If the girl did not love the fellow, she put an empty basket outside as an answer. However in this case the girl could expect a sleepless night as her gates could be daubed all over with tar in revenge, or there could be a heap of rubbish and manure left there, which was considered an awful shame. Just the same, eggs thrown into one's gates on the night of the Trinity Sunday testified to the bad character of the house owner and special unfriendliness to him.