What is an Ex Date / Ex Dividend Date. The Ex Date or Ex Dividend Date, is the first day when purchasers of a security will no longer be entitled to receive a previously declared dividend. Stated another way, the ex dividend date is the first day when buyers of the security will no longer be entitled to receive a dividend that the company had prevoisly declared for payment. SecuritiesCE explains Ex Date / Ex Dividend Date. When a corporation declares a dividend for payment to shareholders it must set a date for which owners are entitled to receive the dividend. This date is known as the record date. Based on the record date, FINRA will set the ex dividend date as one bushiness ...