The Feast of the Ascension of Jesus Christ, also called Ascension Day, commemorates the Catholic belief of the bodily Ascension of Jesus into Heaven. Jesus Christ appeared for 40 days prior to his Ascension, Ascension Day is traditionally celebrated on a Thursday, the fortieth day of Easter. However, in some areas it is moved to the following Sunday.
The feast day has been observed snice the 4th century at least, with St Augustine sayings that it is of Apostolic origin, and it was observed long before his time.
God bless you all.