Julian.fromDateTime constructor

Julian.fromDateTime(DateTime utc)

Create a Julian date object from a DateTime object. The time contained in the DateTime object is assumed to be UTC.

utc The UTC time to convert.

Implementation

factory Julian.fromDateTime(DateTime utc) {
  double floor(double v) => v.floorToDouble();

  final year = utc.year;
  final mon = utc.month;
  final day = utc.day;
  final hr = utc.hour;
  final minute = utc.minute;
  final sec = utc.second;
  final msec = utc.millisecond;

  final j = 367.0 * year -
          floor(7 * (year + floor((mon + 9) / 12.0)) * 0.25) +
          floor(275 * mon / 9.0) +
          day +
          1721013.5 +
          ((msec / 60000 + sec / 60.0 + minute) / 60.0 + hr) /
              24.0 // ut in days
      // # - 0.5*sgn(100.0*year + mon - 190002.5) + 0.5;
      ;

  return Julian(j);
}