I guess it is the date paper was uploaded to arXiv because date is mentioned besides the arXiv identifier.

On Thu, Apr 25, 2019 at 12:24 PM Mikael Abrahamsson <swmike@swm.pp.se> wrote:
On Thu, 25 Apr 2019, Mohit P. Tahiliani wrote:

> Hi Mikael,
>
> I see there is a date in this one (on the left, vertically written besides
> the Abstract and Introduction).
>
> It is: '15 Apr 2019'
>
> Is that what you were looking for?

*sigh* Yes, thanks. But is this actually the paper date or the date it was
uploaded to arXiv?

--
Mikael Abrahamsson    email: swmike@swm.pp.se