Removed countdownTimer correction duration

I was originally going to use this as the number of seconds to wait
before correcting the remaining time. This was to fix the errors that
would comes from just waiting 1 sec for each tick. A little bit of error
would build up each time depending on how fast the javascript was
running. But I decided that the correction wasn't needed since this time
wasn't that important and users would be unlikely to be using this page
long enough for it to matter.
Fixed countdown timer behavior if date has passed

Code would previously alert for timer completion even if the date had
already passed