code: function d2g(jdn) {
  		var j, i, gd, gm, gy;
  		j = 4 * jdn + 139361631;
  		j = j + div(div(4 * jdn + 183187720, 146097) * 3, 4) * 4 - 3908;
  		i = div(mod(j, 1461), 4) * 5 + 308;
  		gd = div(mod(i, 153), 5) + 1;
  		gm = mod(div(i, 153), 12) + 1;
  		gy = div(j, 1461) - 100100 + div(8 - gm, 6);
  		return	{
  			year: gy,
  			month: gm - 1,
  			day: gd
  		};
  	}
docs: /*
  Calculates Gregorian and Julian calendar dates from the Julian Day number
  (jdn) for the period since jdn=-34839655 (i.e. the year -100100 of both
  calendars) to some millions years ahead of the present.
  @param jdn Julian Day number
  @return
  gy: Calendar year (years BC numbered 0, -1, -2, ...)
  gm: Calendar month (1 to 12)
  gd: Calendar day of the month M (1 to 28/29/30/31)