The Ex-Dividend Date, or ex-date for short, is one of four stages that companies go through when they pay dividends to their shareholders. The first stage is the declaration date, which is when the company announces that it will pay a dividend. The second stage is the record date, which is when the company determines who its shareholders are.The third stage is the payment date, which is when the company actually pays out its dividend. And finally, there's the ex-date, which marks the beginning of a three-day period during which new investors cannot buy shares in a company and still receive its most recent dividend payout.