I was trying to express the word snacks, which my friend shared with me that it is called "おやつ", or "お八つ”。 I subsequently found the related expression of "やつどき", or "八つ時”。
a) What is this system of telling time which talks about this 8th hour? Is it still used or relevant?
b) why are snacks called "お八つ”? Are there other commonly used terms?