That's an argument from silence brother.
Ha ha, that's what the gay people claim when trying to justify their sexual perversion.
They claim being gay is A-OK because Jesus never specifically addressed their perversion.
The joke is on them because Jesus gave us the definition of marriage as being between 1 man and 1 woman as being the only time sexual activity is acceptable before the Lord meaning any and all things outside of the definition the Lord gave us is not acceptable to the Lord and as such is rejected.
The abortionists claim whacking babies is A-OK but the joke is on them because the Lord said in His Word that the shedding of innocent blood is an abomination unto Him (Proverbs 6:16-19) and none are more innocent that a little baby in the womb
The point here is the Lord never instructed anybody to make or observe a holiday based on His birth or His resurrection, nor does He have any repercussions listed in His Word for those that do not observe these m an made holidays.
This is all very similar to the Saturday Sabbath arguments - The Lord and His Apostles never instructed anybody to observe this either.
So people can observe these days if they want, but this can easily become idolatry and many have taken it that far and others go so far as to claim a person cannot be saved unless they observe these man-made holidays that the Lord never instructed anyone to observe and never said there were repercussions for the non observant
So now and then I eat a burger, according to your understanding of Scripture, is it a sin?
If you do not eat hamburgers in faith then yes it is a sin.
Romans 14:22,23
Hast thou faith? have it to thyself before God. Happy is he that condemneth not himself in that thing which he alloweth.
And he that doubteth is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.