preveri-datum/src/index.js

export const prviDelovniDan = (datum) => {
  var free = [
    "-01-01",
    "-01-02",
    "-02-08",
    "-04-27",
    "-05-01",
    "-05-02",
    "-06-25",
    "-11-01",
    "-12-26",
    Easter(datum.getFullYear()),
  ];
  var d = new Date();
  for (var i = 0; i < free.length; i++) {
    free[i] = d.getFullYear() + free[i];
  }
  d = new Date(datum);
  if (
    free.indexOf(datum) == 0 ||
    free.indexOf(datum) == 1 ||
    free.indexOf(datum) == 4 ||
    free.indexOf(datum) == 5
  ) {
    d.setDate(d.getDate() + 2);
  } else if (
    free.indexOf(datum) == 2 ||
    free.indexOf(datum) == 3 ||
    free.indexOf(datum) == 6 ||
    free.indexOf(datum) == 7 ||
    free.indexOf(datum) == 8 ||
    free.indexOf(datum) == 9
  ) {
    d.setDate(d.getDate() + 1);
  }
  if (d.getDay() == 0) {
    d.setDate(d.getDate() + 1);
  } else if (d.getDay() == 6) {
    d.setDate(d.getDate() + 2);
  }
  console.log(d);
  return d;
};
function Easter(Y) {
  var C = Math.floor(Y / 100);
  var N = Y - 19 * Math.floor(Y / 19);
  var K = Math.floor((C - 17) / 25);
  var I = C - Math.floor(C / 4) - Math.floor((C - K) / 3) + 19 * N + 15;
  I = I - 30 * Math.floor(I / 30);
  I =
    I -
    Math.floor(I / 28) *
      (1 -
        Math.floor(I / 28) *
          Math.floor(29 / (I + 1)) *
          Math.floor((21 - N) / 11));
  var J = Y + Math.floor(Y / 4) + I + 2 - C + Math.floor(C / 4);
  J = J - 7 * Math.floor(J / 7);
  var L = I - J;
  var M = 3 + Math.floor((L + 40) / 44);
  var D = L + 28 - 31 * Math.floor(M / 4);
  return "-" + padout(M) + "-" + padout(D + 1);
}
function padout(number) {
  return number < 10 ? "0" + number : number;
}