Christianity actually has a long history of co-opting holidays.
One can view it as merciful or strategic (or both). The timing of Christmas seems to have been to make it easier to replace Mithras. Easter obviously absorbed some spring-festival components, as many local developments of Christianity tended to do. There were actually even crosses made that were one-half Thor's hammer (only thing that actually stopped those vikings!). This was thought of not as a savagery and a pagan war on Christmas, but as a positive accessory to spreading Christian values (see again: vikings stop raiding Europe).
What's fascinating about Easter is that it seems an agreed upon replacement day of celebration, the agreement of which has been forgotten.
Leviticus 23:5,6 - Day 14 is Passover, Day 15 begins the Feast of Unleavened Bread
Acts 12: 1-5: Peter was arrested and imprisoned sometime on or after day 15, and his captor intended to bring him out "after Passover" (which presumably already happened)
(source: KJB or NABRE, your choice)
Either there was agreement that Passover was part of the full string of holy days that all got referred to as "Passover" at some point; a word "sometime" was missing before "after Passover;" or else, there may have been another holiday, because it was already after Passover that Peter was imprisoned. Even those who argue that Easter is "real," are arguing that it's real in as much as they celebrate a particular list of significant events on a day they call Easter. Those who argue it is not real are celebrating those same events more closely to when they believe you're supposed to.
I think the idea that a day has a cosmic connection to itself in another year is kind of unnecessary, because days don't really match well that way! It seems more important that the celebratory (whenever) gets remembered.
And if you're a real language nut, I offer you German, the root for the basic structure of English, with a somewhat more convincing and recent root for "Easter":
"Because the English Anglo/Saxon language originally derived from the Germanic, there are many similarities between German and English. Many English writers have referred to the German language as the 'Mother Tongue!' The English word Easter is of German/Saxon origin and not Babylonian as Alexander Hislop falsely claimed. The German equivalent is Oster. Oster (Ostern being the modern day equivalent) is related to Ost which means the rising of the sun, or simply in English, east. Oster comes from the old Teutonic form of auferstehen / auferstehung, which means resurrection, which in the older Teutonic form comes from two words, Ester meaning first, and stehen meaning to stand. These two words combine to form erstehen which is an old German form of auferstehen, the modern day German word for resurrection.7 (Italics in original)"
This becomes more compelling when you realize everything from our simple sentences to our names of weekdays are Germanic in origin ("Wednesday" is spelled that way because it used to be Woden's Tag, or Odin's Day, and now we basically are saying "Wendz-day")