whats the difference between ex-*** dividends?

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1. The ex-dividend date, also known as the reinvestment date, is an investment term involving the timing of payment of dividends on stocks of corporations, income trusts, and other financial holdings, both publicly and privately held.

2. In the United States, the IRS defines the ex-dividend date as "the first date following the declaration of a dividend on which the buyer of a stock is not entitled to receive the next dividend payment.

3. The London Stock Exchange defines the term "ex" as "when a stock or dividend is issued by a company it is based upon an "on register" or "record date". However, to create a level playing field when shares are traded on the London Stock Exchange during this benefit period an "ex" date is set. Before this "ex" date if shares are sold the selling party will need to pass on the benefit or dividend to the buying part

http://en.wikipedia.org/wiki/Ex-dividend

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