YYYY-MM-DD
This is the only rational order to write dates when you're representing them all as numbers. It is a logical, descending progression that keeps things sorted coherently on computers if you write the date at the start of a file name.
Conversely, if you are writing out the name of the month (e.g., "March"), then do whatever you want, honestly. People's brains can figure out what the deal is just fine from that written context clue. If they can't, they're either being willfully stupid or naturally stupid. Neither type of stupidity deserves your time or energy to address.
















