This is entirely state-by-state; there's no federal law that covers it. As such, the exact terms vary pretty widely; in many cases there is no requirement if yo

This is entirely state-by-state; there's no federal law that covers it. As such, the exact terms vary pretty widely; in many cases there is no requirement if you have n hours (sometimes 2) before or after work when the polls are open; the time can be unpaid in many cases, which can make it a difficult choice for people paid hourly. It's also not really expressed as an affirmative mandate per se; you have to request time off, in some cases it's the employer's choice when the time is taken, and if they "retaliate" or fire you then you can complain after the fact. So now you're in a dispute with your employer and you missed your chance to vote...hooray.