Learning About Ascension Thursday

Jennifer Gregory Miller wrote an article that was published by CatholicCulture.org  entitled The Solemnity of the Ascension: The Feast Who Was Thursday.  It is very detailed.  Quoted below are selected portions from two of the paragraphs that give a brief overview of the Lord's ascension [1]:

This [past] week was often referred to as Rogation Week before the revision of the calendar in 1969, and the Solemnity of the Ascension is traditionally celebrated on Thursday. But much of that has changed, or varies depending on where one lives.

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Originally the early Church celebrated the fifty (50) days of Easter to Pentecost as a whole. It wasn’t until the fourth century that the fortieth (40th) day was marked by the feast of the Ascension, and then the fiftieth (50th) marked by Pentecost to close the Easter season.

[1] https://www.catholicculture.org/culture/liturgicalyear/blog/index.cfm?id=134