Just for Microsoft's information, since this annoyance has been around for decades and they don't seem to care to change it - Google Sheets automatically treats any date exactly the way I entered it: 9/1, 09/01, 9/1/18, 9/1/2018, etc. And they can do the math on any of those date formats without being told it's a date. So, it can't be hard to do this, but MS doesn't want to???



If you aren't afraid of the competition, then by all means continue to ignore the millions of users who hate the 3-Sep date format.