Is holy day biblical?

Some preachers have tried to fix the days of Christ crucifixion and his resurrection in different days.

But right now, the argument isn't about the exact day. Because till date there is no valid proof of Christ date for crucifixion and resurrection.

To me I believed what we should be more concerned about is the fact that Christ came and died for us, and on the third day, he rose again that we may have life and have it in abundance.

We should reflect on how he agreed to lay down his life for us to be free from all forms of affliction. This must be real and through love.
Today, we are who we are because of the finished work on the cross.

So let's rejoice together because Christ has risen.