Why? Don't those other days belong to the God of Israel? Did a pagan god make the 13th and the 15th of Nisan?
I'm not under the covenant God made with Moses, no matter how much you'd like to force me into it. Scripture says Christ came to establish a better covenant. I'll go with that better covenant, thanks.
Why do you think Paul wrote to the Galatians that if they had themselves circumcised, Christ would do them no good?
The feast days are commanded by YHvH forever. I don't believe impugning the Holy Word of Elohim Easter and Christmas are of haSatan not YHvH. cite please
shalom b'SHEM Yah'shua HaMashiach Adonai
with Pagan feast days is praising the Holy Name of HaShem.