There is no "april 30 dividend". PFE last paid a div 3/5/13.
What you are asking for is PFE's next ex dividend date. "Ex" means without. Buy on the ex date and you don't receive the next dividend payment. If you want the dividend, be sure to buy the day before the ex date or earlier. The next ex div date is forecast to be 5/8 according to a subscription Bloomberg terminal.
One thing you should be aware of is that dividends are not free money. All else equal, on the ex div date, a stock's share price is adjusted DOWNWARD the amount of the dividend. Makes sense if you think about it.
Since a buyer on ex date is not gettig the current div, the shares are worth the closing price of the day before less the div.