Michael Valentine Jones (1/9/2013)
Jeff Moden (1/9/2013)
So, which "standard" are you going to use for someone that is born on a leap year day? Feb 28th or Mar 1st? 😉
As usual, no one agrees on this, but different countries do at least have some standard.
http://en.wikipedia.org/wiki/February_29
"...in England and Wales or in Hong Kong, a person born on February 29, 1996, will have legally reached 18 years old on March 1, 2014. If he or she was born in the United States, Taiwan or New Zealand, he or she legally becomes 18 on February 28, 2014, a day earlier..."
I prefer the Feb 28 date for birthdays in non-leap years because that's the "standard" for the US. And, it's easier to code in TSQL.:-D
I hate to say it, but there is not actually a "standard" the U.S. - it depends on the precise purpose you're doing the date calculations for, and who needs them. Check with the business users about this, every time, particularly in regulated industries for for regulated/legal purposes.