date-fns/esm/_lib/startOfUTCISOWeekYear/index.js

Modern JavaScript date utility library

import getUTCISOWeekYear from '../getUTCISOWeekYear/index.js';
import startOfUTCISOWeek from '../startOfUTCISOWeek/index.js'; // This function will be a part of public API when UTC function will be implemented.
// See issue: https://github.com/date-fns/date-fns/issues/376

export default function startOfUTCISOWeekYear(dirtyDate) {
  if (arguments.length < 1) {
    throw new TypeError('1 argument required, but only ' + arguments.length + ' present');
  }

  var year = getUTCISOWeekYear(dirtyDate);
  var fourthOfJanuary = new Date(0);
  fourthOfJanuary.setUTCFullYear(year, 0, 4);
  fourthOfJanuary.setUTCHours(0, 0, 0, 0);
  var date = startOfUTCISOWeek(fourthOfJanuary);
  return date;
}