If you had said this to anybody before the fourteenth century you would not have been understood. But after that the word “festival” was beginning to be applied to a feast-day of the church. If you had mentioned it to Shakespeare he would have asked you, “Festival? Do you mean the noun or the adjective?”
As a noun he used it in Henry VI, Part I when Charles the Dauphin, speaking of Joan of Arc, says:
Her ashes…
Transported shall be at high festivals
Before the kings and queens of France…
As an adjective he used it in King John:
…this blessed day
Even in France shall be kept festival.
“Festival” to denote a musical performance did not become common usage until the nineteenth century. Mrs. Gaskell mentioned the Worcester Festival in a letter written in August 1857 and soon the word was used to describe other cultural events of importance, as it is today.
So please, whatever you do, don’t say to anybody “Enjoy the Festival” at Christmas time.
That’s nonsense.
Today’s feast is a festivity but of course not at all, in our terms, a festival.
Eric Koch’s book, The Weimar Triangle, is available at Indigo-Chapters and in your local bookstore. 
