PENTECOST (also called Whit-Sunday) (Pente is Greek for 50) Before He died, Christ promised His Apostles that he would help them to spread the Good News. Upon His death, they were distraught because they were left to go throughout the empire without Jesus' guidance.
50 days after His death, the Holy Spirit descended and visited the Apostles. The HS endowed spiritual and mental gifts upon the Apostles. Most notable was the Gift of Tongues.
This day is often called the birth of the Church.
EPIPHANY Generally celebrated on January 6 it marks the baptism of Jesus and the visitation from the Magi. This date is where Christians get the term "12 Days of Christmas".
Epiphany is a Greek word meaning "to make known". The baptism of Jesus and His finding by the Magi were the beginnings of His being revealed to the world.
The significance of the Magi was that they were the first Gentiles (non Jews) to acknowledge Jesus as the son of God. This act shows that Jesus was sent here for all people, all nations, all races.
The day is often used as a time of healing the divisions of prejudice and bigotry and promoting fellowship and brotherhood.
LENT Lent is the forty day period before Easter. It begins on Ash Wednesday and ends at sundown on Holy Thursday with the beginning of the mass of the Last Supper. When counting the 40 days Catholics do not include Sundays. The Tuesday prior to Lent is often a time of festivity due to the somber 40 days that are to follow (Mardi Gras = fat Tuesday, Carnivale = farewell to meat).
Christians follow the Lenten tradition to commemorate Christ's soul searching trip into the desert. Hence, Christians do the same for 40 days. They are expected to look inward to find and correct their own problems. It is also a time of sacrafice.