I never downvote people on Lemmy but I did for this one .... I just spent the past month going through some invoicing and paper receipts and it is absolutely infuriating to still see some businesses using MM-DD-YY while others insist on DD-MM-YY and some businesses have invoicing and receipt printers that use one or the other but not the same. It's not a big deal if you are dealing with documents that are a month or two old because you can guess from what time period they come from ... but it is absolutely confusing if documents get older than that.