Is the King James Bible's translation of 'Easter' incorrect? I do not believe so, because then it would be a faulty translation of the Bible among the rest.
The King James Bible’s use of the English word “Easter” for the Greek word Pascha in Acts 12:4, among its 29 New Testament occurrences, which are all translated as “Passover” except this passage, is a deliberate and divine choice to highlight the resurrection of our Lord and Savior Jesus Christ. It is not an error, reflecting the KJV’s purity as the Word of God in English.
Acts 12:3 KJV And because he saw it pleased the Jews, he proceeded further to take Peter also. (Then were the days of unleavened bread.)
Acts 12:4 KJV And when he had apprehended him, he put him in prison, and delivered him to four quaternions of soldiers to keep him; intending after Easter to bring him forth to the people.
In this passage, the context is set during the “days of unleavened bread” (Nisan the 15th through the 21st), where “Easter” refers to the resurrection on the Feast of Firstfruits (Sunday, Nisan the 16th), which is very distinct from the pascha Passover on Friday, Nisan the 14th which is remembered as Good Friday today, when Jesus was crucified as our “passover” lamb.
John 19:14 KJV And it was the preparation of the passover, and about the sixth hour: and he saith unto the Jews, Behold your King!
1 Corinthians 5:7 KJV Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:
The word 'Easter,' from the Old English ēastre, meaning 'dawn' or 'east,' perfectly captures the distinction between the Old Testament Passover and aligns with the resurrection’s timing at dawn, as the sun (Son) rises in the east. This symbolizes the moment when our Day Star and Savior, the Light of the World, rose again.
2 Peter 1:19 KJV We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: