Ex-dividend date
The date from which a new buyer of a stock no longer gets its next dividend. You must own the shares before this date to be paid.
The ex-dividend date is usually the same as the record date, the day you must be on the company's books as an owner. If you buy on or after the ex-dividend date, the seller gets that payment.
On the ex-dividend date, a stock's price may fall by about the amount of the dividend, because that cash is leaving the company.