Those seasoned enough to have celebrated that quirky half birthday know that in all subsequent years, the IRS requires distributions from those retirement accounts which have received years of tax deferral, known as RMDs, or Required Minimum Distributions.

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In Scotland, the school year starts in August and children start school some time between the ages of four and a half and five and a half, depending on when their birthday is.

BBC: Summer-born hit by school streaming

In parts of Ethiopia, half the girls are married before their 15th birthday.

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Across Manila in sprawling Rizal Park, Estrada told half a million people gathered to mark the birthday of Mike Velarde, charismatic leader of the Catholic movement El Shaddai, that his opponents had it all wrong.

CNN: The Battle Lines Form

When you look at the statistics -- and Secretary Sebelius talked about some of them -- but more than half of obese children become overweight before their second birthday.

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Even granny's 80th birthday is more likely to be held in a posh hotel with guests travelling half around the world to be there, with everyone pitching in to buy her a cruise around the Mediterranean.

BBC: Why has everything become a costly milestone event?

At 77 -- his birthday is July 18 -- he would be, by a decade and a half, the oldest American to go into space.

CNN: It's official: Glenn will return to space