monthCountFromTibetan static method

dynamic monthCountFromTibetan(
  1. Map<String, Object> _a
)

COUNT MONTH FROM TIBETAN DATE

Implementation

static monthCountFromTibetan(Map<String, Object> _a) {
  int year = _a['year'] as int;
  int month = _a['month'] as int;
  bool isLeapMonth = _a['isLeapMonth'] as bool;

  /// the formulas on Svante's paper use western year numbers
  var wYear = year - YEAR_DIFF;
  var solarMonth = 12 * (wYear - YEAR0) + month - MONTH0;
  var hasLeap = isDoubledMonth(year, month);
  var isLeap = hasLeap && isLeapMonth ? 1 : 0;
  return ((67 * solarMonth + BETA_STAR + 17) / 65).floor() - isLeap;

  /// return Math.floor((12 * (year - Y0) + monthObject.month - ALPHA - (1 - 12 * S1) * isLeap) / (12 * S1));
}