lib/gcli/types/date.js
function isDate(thing) {
  return Object.prototype.toString.call(thing) === '[object Date]'
          && !isNaN(thing.getTime());
}
function isDate(thing) {
  return Object.prototype.toString.call(thing) === '[object Date]'
          && !isNaN(thing.getTime());
}
function isDate ( thing ) { return Object . prototype . toString . call ( thing ) === '[object Date]' && ! isNaN ( thing . getTime ( ) ) ; }
Is |thing| a valid date?
@see http://stackoverflow.com/questions/1353684/detecting-an-invalid-date-date-instance-in-javascript
Is |thing| a valid date?