swift date - timesstamp

http://tieba.baidu.com/p/3319268782

>>https://github.com/kevinlawler/NSDate-TimeAgo

good>>http://blog.csdn.net/btqnit/article/details/41722173


逆向取值 https://www.mav3r1ck.com/epoch-converter/
let epochTime = NSTimeInterval(1412440000)
let myDate = NSDate(timeIntervalSince1970: epochTime)
println(myDate)

各語法比較
http://tool.lu/timestamp/

https://github.com/kevinlawler/NSDate-TimeAgo