There are no real answers to these. Explanations for linguistic rules are no more than ways of remembering them. Different languages, even when the same concepts apply to them, have different rules about them. For example, “Curiosity killed the cat” vs. “La curiosité a tué le chat.” French uses the definite article more than English does. Why? It just does. Russian doesn’t have articles at all. In fact, over- or under-use of “the” is one of the main signs that tells me that the writer is a foreigner.
English treats month and day names as proper nouns, so capitalises them; French does not, while German capitalises everything. Go back a few centuries and English capitalised every important noun, and the really important ones would get caps and small caps.
There are no real answers to these. Explanations for linguistic rules are no more than ways of remembering them. Different languages, even when the same concepts apply to them, have different rules about them. For example, “Curiosity killed the cat” vs. “La curiosité a tué le chat.” French uses the definite article more than English does. Why? It just does. Russian doesn’t have articles at all. In fact, over- or under-use of “the” is one of the main signs that tells me that the writer is a foreigner.
English treats month and day names as proper nouns, so capitalises them; French does not, while German capitalises everything. Go back a few centuries and English capitalised every important noun, and the really important ones would get caps and small caps.