[Aardwolf]

Why is it, by the way, that papers have the author names at the top but not the date? The dates are added to papers in references, so why not the date of this paper itself too?

This one happens to have "Workshop track - ICLR 2018" at the top so has some dating, but most don't even have that

[GuiA]

Papers are published in journal/conference proceedings/etc. that will have the date of the issue ("Transactions for the International Symposium on Computational Yak Shaving 2018"). The paper might have been written in 2017, but published in 2018, which means that when it gets cited it will be as "ABC et al., 2018".

Papers without a date are usually preprints, or published independently (e.g. on the author's website) while expecting actual publication at some point.

[tsomctl]

That's the nice thing about arXiv. The first four digits of the paper's number tells you the month and year it was first published.

[JadeNB]

> The first four digits of the paper's number tells you the month and year it was first published.

I think "published" should be "submitted" there. (I suppose that one could argue for regarding submission to the arXiv as publication, especially given the presence of overlay journals—but probably that's not what you meant.)