LONDON -- If you want to be eligible for a dividend payment, or if you're hoping a share price might drop disproportionately when the time has passed, you need to be aware of your ex-dividend dates; so long as you hold the shares up to and including that day, you'll get your money.

Whatever your strategy, we have a handful of FTSE 100 companies reaching the all-important day next week. The following three will go ex-dividend next Wednesday, May 8.

GlaxoSmithKline (LSE:GSK) (NYSE:GSK)
GlaxoSmithKline released first-quarter results on April 24 and announced a dividend of 18 pence per share. That's a rise of 6% over the same period last year and is part of a program of returning cash to shareholders; the pharmaceuticals giant is also targeting share repurchases of 1 billion pounds to 2 billion pounds.

A similar percentage rise in the firm's dividends over the full year would result in a total payment of approximately 78 pence per share for a yield of 4.7% on a share price of 1,658 pence.

Antofagasta (LSE:ANTO)
The mining sector might be under some pressure these days, but that hasn't stopped Antofagasta from offering a nice dividend for the 2012 full year. Although the ordinary dividend of $0.21 per share announced on March 12 only represents a yield of 1.5% on a share price of 909 pence, there is also a special dividend of $0.775 per share to be paid, taking the total for the year to $0.985 for a yield of 6.9%.

The previous year's dividend payment was similarly split, but with an ordinary dividend of $0.20 and a special dividend of $0.24 per share for 2011, the total payout for 2012 is up 124%.

Kingfisher (LSE:KGF)
On March 26, Kingfisher announced a final dividend of 6.37 pence per share, unchanged from the same period last year. But an earlier 25% rise in the interim dividend to 3.09 pence takes Kingfisher's overall payment for the year to 9.46 pence per share. That's a rise of 7% and represents a yield of 3% on a share price of 327 pence.

The boost comes despite the fact that a 2.4% drop in sales for the owner of the U.K.'s B&Q and Screwfix brands led to an 11.4% fall in adjusted pre-tax profit and an 11.2% fall in adjusted earnings per share. But the dividend was more than twice-covered, and there is a return to earnings forecast for the current year.

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