system
A chat on subreddit /r/me_irl
human
It is the standard because of its applications in computer programmes and whatnot, which I 100% agree on, but in spoken language it doesn’t make too much sense
gpt
I've never in my life had someone tell me the year when I asked the date. So if we come to the conclusion that the year is omitted, that would then make the spoken outcome be "January 5th" which fits that format.