Why the iPhone Timer app displays a fake time

Everyone is saying "rounding, duh" but that a bit unfair IMO

You should show each integer value second for, ideally, one second (in the case with no display for fractional seconds). So the question is: exactly what rage of time to cover? The poster expected that for second N, it would be:

[N,N+1)

But Apple seems to do:

[N-0.5, N+0.5)

I think the Apple behavior makes perfect sense when you are displaying the current time (eg like a watch). It may be a little less obviously correct for the timer case, but still seems fine. I'd bet they implemented it for the time of day case and just re-used it for the timer case.

Only at 0:00. That's a separate feature, showing 0:01 at a minimum for a paused timer (presumably to make it very clear that you aren't looking at an expired timer, even though the UI disappears for an expired timer.)

Is this the fencepost problem but with time :P?

That was the solution as well for my primetimer app, funny that I had the same findings

I've never seen something so confusing. I've been (and quite frankly still am) seriously considering this is a big prank that's going over my head. The author even mentions that because time goes up and countdowns go down, rounding down is confusing. Wouldn't the logical conclusion be that you needed to round up?

Wouldn't rounding up be the most logical option ANYWAY? If someone counts me down, I expect them to say "5, 4, 3, 2, 1, GO", and I expect a timer to do the exact same thing. This fixes seemingly every issue, starting on 5, not having to round to nearest integer (or add 500ms, which is an odd way to look at it, but sure), and not showing 0 (which I'd find quite weird). I just checked my own (Android) timer, and sure enough it rounds up, which is what I expected and what I expect from a countdown in general.

Maybe what seems to me like the most obvious behaviour for a timer is not as obvious as I think, but why did the author not even mention rounding up as a solution, or how it could conflict with his own expectations?

I'll just assume this to be a shower thought that didn't fully mature before making it into an article, but there seems to be enough effort that I'm still left quite confused. Oh and don't mistake this for a euphemism for me critiquing the intelligence of the author, at worst it's just a funny blindspot (as we all experience) but I'm seeing very little mentions in the comments here, which only adds to my bafflement.