Any festival other than Eid-Al-Adha or Eid-Al-Fitr is essentially haram. No birthday parties, no anniversary parties, no graduation parties, no nothing, lest we be immitating the Kuffar.
So we should invent a new holiday: the atheist Ramadan.
Initially it's identical to Ramadan and celebrated identically. Except without any belief in Allah.
But every now and then some tiny subtle changes are added and/or removed to the way it's celebrated.
That way in a few decades or centuries every Muslim will be utterly confused and will not know if the way they are celebrating Ramadan is the genuine original way or it's an imitation of atheist-Ramadan.
And their brains will explode.