I should have said the juice is worthless/dangerous if not drank soon after juicing it. I never store juice. I drink it immediately. I know people who do juice and store it for 24 hours. They fill the jar up to the top where it is overflowing and then put the lid on it. They believe this helps with oxidation. It does not appeal to me, however.
Oh, to answer your question. Yes, I have seen day old carrot juice and No I don't believe I have ever tasted it. Juice should be drank within minutes of juicing.