/jp/ - Otaku Culture

五月五日は祝日です

I know kanji have different readings based on context, the question is, do I approach it by learning the different words those kanji have different readings in by "brute force", such as knowing that 五月 is always read like that, or is there a rule that tells me which way to read the kanji? As in, if the kanji is in a word, it's read A, if it's in a full sentence it's read B. Sorry for asking in such a spoonfeed manner, I'm just a bit lost with this.