The information is implicit in every case, that it happened on the most recent instance of that date.
It's 11/7/26 today.
7th? Happened 4 days ago. January? Happened 6 months ago. 90s? Happened 30 years ago.
You're being intentionally obtuse. Nobody is claiming confusion. (It's also somewhat moving the goalposts, but we'll ignore that). Unless it's a written article, in which case the month will be outdated in a year anyway, and it's bad practice to not specify the full date.
you say that like its not arbituary.
How is going from small -> big or big -> small somehow more arbitrary than starting in the middle of that scale?