Originally Posted by Drip

For the race on Monday, we have to vote for the 20x payout now.
For the final race on Tuesday, we have to vote for the 100x payout tomorrow.

(Strangely, I found Nitty's list the most comprehensible to follow)

Although bear in mind that the window between getting the race results and spending the rewards Tuesday morning is going to be very small (as happens every time an event ends).

I really wish they'd make the exchange available for one more day after an event ends.