According to your post The Voice
is on both Tuesday and Thursday on the NBC site. My guess is you are seeing a old copy of the Tuesday, Nov. 6 page from your browser's cache. If you use Windows, press CRTL-F5 to refresh the page for most browsers.
The new Zap2it should show you the correct info.
Here is the NBC announcement of the schedule change:
Breaking News - NBC Expands Election Coverage on Tuesday; Bumps "The Voice" Recap to Thursday | TheFutonCritic.com