Q:

Countdown timer is off by 1 interval

I tried to choose a answer for a question on SA and someone immediately answered with the correct response. I try to click the check box and it says wait 2 min. I keep clicking until it changes from 2 min to 1 min. I wait 60 seconds on my watch and click again and it says please wait 59 seconds.
The 2 minute mark should have said 3 and the 1 minute mark was really 2.
It seems that this has escalated to hours, which is a lot more inconvenient than 59 seconds.

A:

Hypothesis
I'm pretty sure the issue is that above 60 seconds the system only shows the minutes left, and truncates the seconds.
So when it shows "You can accept an answer in 8 minutes" then it's really saying, "You can accept an answer in 8:xx minutes:seconds where seconds ranges from 0 to 59"
So on the transition from 2 minutes remaining to 1 minute remaining, as displayed, you actually are changing from 2:00 to 1:59, and thus still have over 1 minute remaining.
Test
Well, a test question I just tried shows this behavior:
https://meta.stackexchange.com/questions/45826/test-question-please-avoid-upvoting-will-be-defenestrated-in-15-minutes/45828#45828
It is deleted, but 10k and admins can see it for debugging purposes should they decide to make a change.
Results
Here's my time stamped comment log:

"You can accept an answer in 2 minutes" – Pollyanna 3 mins ago edit
  "You can accept an answer in 1 minute" – Pollyanna 2 mins ago edit
  "You can accept an answer in 59 seconds" – Pollyanna 1 min ago edit

Which clearly shows this behavior
Conclusion
Programmers, being picky as they are, should probably be given a more precise notice:

Round up and change the wording to "You can accept an answer in about 2 minutes"
Get rid of the seconds countdown altogether (or, alternately, only round up if more than 59 seconds)

This would result in the following comment log:

"You can accept an answer in about 3 minutes" – Pollyanna 3 mins ago edit
  "You can accept an answer in about 2 minutes" – Pollyanna 2 mins ago edit
  "You can accept an answer in about 1 minute" – Pollyanna 1 min ago edit

Or 

"You can accept an answer in about 3 minutes" – Pollyanna 3 mins ago edit
  "You can accept an answer in about 2 minutes" – Pollyanna 2 mins ago edit
  "You can accept an answer in about 59 seconds" – Pollyanna 1 min ago edit

