When will episode 4x04 be on?

I know it's always on Thursdays but I thought I saw on the CW website that it would be on Wednesday. I want to be sure. Plus I am confused because I thought 90210 would be on tonight like it usually is on Mondays, but it isn't. So if 90210 isn't on then TVD might have changed too. If anybody can tellme when either of the shows will be on I would be extremely greatful.