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.

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 1.

Wednesday is the day for ITV after the television company declared a final dividend of 1.8 pence per share on March 21. That takes the total dividend for the year ending Dec. 31 to 2.6 pence per share for a yield of 2.5% on the year-end share price of 105.2 pence. Since then, the price has risen to 127 pence, bringing the yield down to 2.1% on today's price.

But an ordinary annual dividend is not all shareholders will enjoy: There will also be a special dividend of 4 pence per share. We were told: "Over the last three years we have made significant progress in transforming the Group-commercially, creatively and financially."

Admiral (LSE:ADM)
On March 6, insurer Admiral Group announced a 20% rise in its dividend for the full year to December 2012, with a final dividend of 45.5 pence per share taking the total up to 90.6 pence. Based on December's closing share price of 1,160 pence, that represented an attractive yield of 7.8% -- and even on today's price of 1,349 pence, it's still 6.7%.

Those dividend levels look unlikely to be maintained, however, with City analysts currently forecasting a fall to around 83 pence per share for 2013 and 74 pence for 2014.

Weir Group will go ex-dividend with respect to its 30 pence final dividend, announced on Feb. 27. For the full year to Dec. 28, the engineering group, which caters to the mining, power, and oil and gas industries, is set to pay a total dividend of 38 pence per share. That's a 15% rise on 2011's payment and amounts to a yield of 2% based on the Dec. 28 share price of 1,876 pence. Once again, the price has risen, taking the yield down to 1.8% on today's price of 2,175 pence.

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Alan Oscroft has no position in any stocks mentioned. The Motley Fool recommends Weir Group. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.