But that’s wrong. A freestanding number is NEVER the day of the month. Those always have the name of the month next to them. As I write this posts from yesterday say “Sep 23”. They NEVER say just “23”.
I agree that the apostrophe on a shortened year number is easy to overlook. But the 3-letter month abbreviation is hard to overlook. If there isn’t a month in words, then the number you see is a year. Always and everywhere.
I’m not understanding what you’re saying. The only difference on this website is a little tick mark next to the [date]/[year] which differentiates the two, for instance here which has time field containing “Mar '19”. Here, some posts say “Sep 20”. Both are three letter abbreviations of months, followed by a blank, followed by an optional tick mark, followed by one or two numbers. No free-standing numbers involved.