For normal dividends, the record date is used to establish the ex-date. Under normal dividend rules, the ex-date is two business days before the record date. With dividends that are 25% or more of the stock's trading price, the record date isn't used to establish the ex-date; the payment date is used, the ex-date being one business day after the payment date. In such cases, the purpose of the record date is to establish that only the shares outstanding as of the record date are eligible to participate in the dividend. That means that any shares issued after the record date, whether from convertible securities, secondary issues or any other source will not participate.