How deliciously fanciful...
I take the commands of the Lord and believe them when he specifies HIS holy days. He does not mention Easter or Christmas.
I also try to follow (albeit imperfectly) the examples he set while incarnate. These include observing the holy days he himself observed while incarnate. Our duty as Christians is to walk as he walked:
1Jn 2:3 Now by this we know that we know Him, if we keep His commandments.
1Jn 2:4 He who says, "I know Him," and does not keep His commandments, is a liar, and the truth is not in him.
1Jn 2:5 But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him.
1Jn 2:6 He who says he abides in Him ought himself also to walk just as He walked.