How do you know when Apple Music playlists update? Is there a way to know when Apple Music dynamic playlists update? For instance, every Saturday, every day, every month, and so on?

If so, where do I find the day of last update?
I noticed on my iPhone, the date last updated SOMETIMES shows at the top of the playlist in grey text under the playlist name, but not always. Of the three auto updating playlists I am subscribed to, two of them show a date of last updated today, and one shows nothing. I can't find a way to see the date last updated in any playlist in iTunes for Windows, only in the iPhone app.