Oh, come on. Is this really necessary? The dictionary I’m using has separate entries for afternoon and afternoons.
The difference is that afternoons is used to describe something that occurs repeatedly in the afternoon or on any afternoon whatsoever, but definitely in the afternoon.
For example, your afternoons may be free, particularly if you’re unemployed. Or you may have an AA meeting on Sunday afternoons, right after you recover from your Saturday night binges. Or a book club might meet afternoons because they don’t want to start drinking before noon.
This brings up the question of nooners, which is a common colloquialism that is not recognized by my spell checker. Nooners generally refers to sexual encounters that occur over the noon hour and, barring instantaneous ejaculation, therefore typically spill over into the afternoon. If there is a name for that, why aren’t morningers, afternooners, duskers, eveningers, and nighters similar colloquialisms?
Don’t people have sex at those times? True, I’m not getting any, but I would have thought that others are. Noon-only seems rather restrictive.