There’s about seven weeks till Election Day, but voters in most states—except those in Mississippi, Alabama and New Hampshire—will have the opportunity to vote in mere weeks.

For some states, the last day to register to vote is less than a month away. Currently 21 states and D.C. allow voter registration on Election Day, meaning that you can wait until Nov. 5 to register and vote. However, many states require registration as early as the first week in October.