Voting for any given Minted Challenge typically lasts for a few weeks, and we’ll always display the end date on the banner of each challenge page. That said, voting can sometimes be significantly shorter for certain challenges, so please be sure to check!
If you can't find a way to vote on your design, then most likely the voting phase has not begun for that challenge. You can embed a voting badge as soon as you submit a design, but keep in mind that people can't vote on your work until the voting phase starts. Voting begins shortly after the submission phase has closed, typically within a few hours. You can find submission deadlines for each challenge here.