I guess you could ask the same with English. Why do we capitalize our months, days, names of languages? How would you respond to that question? Because it's the rule, that's why!

Actually, we capitalize them because half of them are derived from proper names, either of roman deities or emperors; same goes for the days of the week.

As for why they are capitalized in English it is probably because English follows more after its German heritage of capitalization; whereas, Latin derived languages such as French and Spanish follow the Latin tradition (see link below)

Comparison of Latin, German and English Days of the Week

Actually, we do capitalize the names of the week... when they are proper names, and unique (but not when you refer to any Monday, Tuesday,... of the year):

Jueves Santo

In Spanish I am not sure what the names of the week are derived from, except that

lunes = named after the moon

Sábado = the sabbath

• martes - Martis dies (day of Mars)
• miércoles - Mercuri dies (day or Mercury)
• jueves - Iovis dies (day of Jupiter)
• viernes - Veneris dies (day of Venus)
• domingo - Dominucus day (day of the Lord)

Actually, we capitalize them because half of them are derived from proper names, either of Roman deities or emperors, and apparently English convention felt it made more sense to capitalize all of the months than to only capitalize half of them.

No language is entirely logical in this sense; it is a matter of convention: a caesarean section is not always written with capital C, even though it comes from Julius Caesar. The word "academy" comes from Akademos, a person's name too.

No language is entirely logical in this sense; it is a matter of convention: a caesarean section is not always written with capital C, even though it comes from Julius Caesar.

Yet a Caesar salad is.

The word "academy" comes from Akademos, a person's name too.

I hadn't heard that one. I always thought that the word was handed down to us in the tradition of Plato's academe

Thanks everyone for helping.