בדף: http://www.investopedia.com/terms/r/recorddate.asp
Investopedia explains Record Date
On the record date, a company looks to see who its shareholders or "holders of record" are. Essentially, a date of record ensures the dividend checks get sent to the right people.
בדף: http://en.wikipedia.org/wiki/Effective_date
An effective date or as of date is the date upon which something is considered to take effect. This may be different from the date upon which the event actually occurs or is recorded.[1][2]