Oh really? The Bible nowhere instructs Christians to celebrate holidays such as Christmas, Easter, Thanksgiving, Valentines Day, Memorial Day, Labor Day, Independence Day, birthdays, anniversaries, etc. The Bible mentions several “celebrations” that the Israelites observed: Passover, Pentecost, Purim, New Moon, etc. The difference between these holidays and the holidays celebrated today is that some of our modern Christian holidays have pagan or even anti-Christian origins. Christmas and Easter began as attempts to redefine a pagan holiday with a Christian meaning, i.e., the Easter bunny, the Christmas tree, giving gifts, hunting for eggs, etc.
Sorry, but you are mixing things up all over the place...
First of all, Independence Day, Labor Day, and Thanksgiving Day are US National holidays - Nothing wrong at all with national holidays, especially those giving glory to the Father.
To compare: YHWH's feasts are commanded. Purim and Hanukkah are not commanded and are treated much as we treat our national holidays. Same kind of thing, and therein lies precedence for national praise. As Yeshua participated in both, he gave them sanction. There is no bad day for a nation to offer praise.
Secondly, everyone marks birthdays and anniversaries. There is nothing wrong with days of remembrance. Especially so if offering praise.
And finally, like I said before, I am Christian Messianic. That means I keep all those Biblical feasts, and observe Shabbat, in a Messianic context.
Naturally, That is what I recommend for everyone.
To say more would be to step over a fine line on this board.