Basic Javascript Countdown Timer Taking Longer Than Time Set

Basic Javascript Countdown Timer Taking Longer Than Time Set



I'm trying to code a VERY SIMPLE countdown timer. At first, it seemed to

be done and working fine. I was excited. But then, upon testing it out, I

realized that a 30-min countdown seemed to take for ever. So I looked into

it and found that what my timer was timing as 30 mins was, in the real

world, almost 50 mins!

I've tried debugging the thing and can't find where it's going wrong. At

first I thought maybe the setInterval was responsible and not working at

exactly one second intervals. But I can't see anyone else has had that

issue. Supposedly it should always work. And, when checking it closely, by

making the function print put ...getSecond() data it does seem like it's

working perfectly. However, time is being added on at some point!

I've tried this approach. Getting the info from the new Date() function

and then subtracting the starting timestamp with the the finishing

timestamp... etc., etc. The thing is this was supposed to be a 5-10 min

code work and, thus, complicating it in this way defeats the purpose!

So I'm coming to you guys for help! I've quickly set it up in this

jsFiddle for you guys to try out and hopefully someone out there will see

where the glitch is.

The timer basically just shows the minutes going down, as I don't want it

to count seconds (seconds going by, I find, frustrate people who have to

fulfill a task in a specific time). I've unhidden the seconds so you guys

can see them, though. And it should print out the time it starts and time

it ends, so you can see the difference between the time your setting up

for the countdown and the actual time it takes for the countdown to end.

If one tries out the 1-min countdown, for example, one should find one or

two seconds are added. If one tries out the 30-mins countdown one should

find about 50 mins are added.