My experience is that you must buy the stock 4 days befor the ex dividend date because it then takes three days for the transaction to occur. So at the end of trading three days after you buy the stock you now own the shares and will capture the dividend.
Nope, why not look it up instead of trying to make up the rules yourself.
ex-div means without the div and you need to own at the close of trading on the day before ex-div.
That's all there is to it as you would easily verify by googling the definition of the terms.
"you must buy the stock 4 days befor the ex dividend date because it then takes three days for the transaction to occur."
You're over-thinking it. The ex-date already takes into account the three days necessary to settle the trade by the record date. The ex-date is a real-time date. You can buy a stock as late as the day before the ex-date and qualify for the dividend.
X-div date is Monday, August 12. Because the x-div date is on a Monday, the holders at the close on Friday, Aug. 9th get the distribution. You can sell on Monday (at an x-div reduced price) and still get the dist.
Both responses are WRONG! August 12 is the last day to BUY or HOLD the stock in order to earn the dividend. You must own the stock when the pre-market opens on Ex-Div date to earn the div. In other words, you can sell PER Monday morning Aug 12th and earn the div, but the stock price will be reduced by 58.5 cents from the regular session closing price on Friday. If oil prices, etc. push the stock back up then you will have made money, if it goes down, then you will have lost money (if you sell).