Dial-The-Truth-Ministries (DTTM) attempts to address whether Easter is a mistranslation of "pascha" in Acts 12:4. This page illustrates the mistakes they made.
First there are 29 times the word "pascha" is used in the Bible. In general they all seem to reference the Passover celebrations.
Luke 22:1 says that it drew close to the time of the festival of unleavened bread, which is called pascha.
DTTM says:
After the passover (Exodus 12:13, 14), we find that seven days shall be fulfilled in which the Jews were to eat unleavened bread. These are the days of unleavened bread!
Using this definition of passover, it is clear that "pascha" as used in Luke 22:1 is not the same thing.
Another flaw:
DTTM says:
On the next morning, the 15th begins the "days of unleavened bread."
This completely flies in the face of the Hebrew reckoning of days. In Hebrew tradition, a day starts at nightfall. We can see this even in Genesis 1:5:
And God called the light "Day" and the darkness "Night". And the evening and the morning were the first day.
Note when naming the order is day, night, but the first day was ordered evening, then morning.