I forgot to vote! I didn't know when the poll closed and opened. Seems odd to have the two challenges have different poll periods.
You'll get used to it. It's always the same -- 24th to the 28th for the 75, and 1st to the 15th for the 300. When we first started, it was different every month, but we eventually standardized it so people could remember. The part I always forget is how long the voting is on the tiebreakers, which we do have fairly often, but it's in the post when it happens.