// Implements the Meeus/Jones/Butcher algorithm
// https://en.wikipedia.org/wiki/Date_of_Easter#Anonymous_Gregorian_algorithm
export const getEasterDate = (year: number) => {
  const a = year % 19;
  const b = Math.floor(year / 100);
  const c = year % 100;
  const d = Math.floor(b / 4);
  const e = b % 4;
  const f = Math.floor((b + 8) / 24);
  const g = Math.floor((b - f + 1) / 3);
  const h = (19 * a + b - d - g + 15) % 30;
  const i = Math.floor(c / 4);
  const k = c % 4;
  const l = (32 + 2 * e + 2 * i - h - k) % 7;
  const m = Math.floor((a + 11 * h + 22 * l) / 451);
  const n = Math.floor((h + l - 7 * m + 114) / 31);
  const o = (h + l - 7 * m + 114) % 31;

  return new Date(year, n - 1, o + 1);
};