code: function isSt(date, testOffset) {
        date = date || new Date();
        var offset = testOffset || date.getTimezoneOffset();
        return jsk.hasDst() && offset == jsk.invertedDst();
      }
docs: /*
  ### isDaylightSavingTime([date])
  alias `isDst`
  
  If a date is at daylight saving time (`now` is used if no `date` is specified)
  
  jsk.tz.isStandardTime(new Date(2012, 1, 1)) // for North America/Eastern Time
  => false