I’m sorry but it doesn’t make sense to me. Regardless of the month, I think what matters first is to know what day of the month you are in, if at the beginning, in the middle or at the end of said month. After you know that, you can find out the month to know where you are in the year.
What is the benefit of doing it the other way around?
My guess is the month is most relevant to an agrarian society. It tells you where you are in the growing cycle that the entire culture revolves around. The day and year offer little practical utility to a 19th century farmer.
Oh, that make more sense and seems plausible! Thanks!