What it is
Federal law sets the general election for the Tuesday after the first Monday in November, so it falls between November 2 and 8. Presidential elections are held every four years and congressional elections every two, in even-numbered years. Many states and cities hold local elections on the same Tuesday in odd years.
Is it a day off?
It is not a federal holiday. Several states make it a state holiday, and many states require employers to give workers time off to vote, sometimes paid. Rules differ widely, so check your state's election office.
Most people can also vote early or by mail.
History
Congress set the date in 1845, choosing a Tuesday in November so farmers could travel after harvest without voting on the Sabbath.