[londons_explore]

Unless you pause it... In which case it rounds up...

[furyofantares]

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.)

[throwaway2245]

Ah. I see that my Apple app does do that, but it's not my preference.

I would much prefer "0 seconds remaining" to mean 0 to 0.5 seconds remaining, than any other possible case. I would find it much easier to parse.

(Alternatively, please show more accuracy for this case, where it's likely relevant)