index.js 957 B

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  1. import toDate from "../../toDate/index.js";
  2. import requiredArgs from "../requiredArgs/index.js";
  3. import startOfUTCISOWeek from "../startOfUTCISOWeek/index.js";
  4. export default function getUTCISOWeekYear(dirtyDate) {
  5. requiredArgs(1, arguments);
  6. var date = toDate(dirtyDate);
  7. var year = date.getUTCFullYear();
  8. var fourthOfJanuaryOfNextYear = new Date(0);
  9. fourthOfJanuaryOfNextYear.setUTCFullYear(year + 1, 0, 4);
  10. fourthOfJanuaryOfNextYear.setUTCHours(0, 0, 0, 0);
  11. var startOfNextYear = startOfUTCISOWeek(fourthOfJanuaryOfNextYear);
  12. var fourthOfJanuaryOfThisYear = new Date(0);
  13. fourthOfJanuaryOfThisYear.setUTCFullYear(year, 0, 4);
  14. fourthOfJanuaryOfThisYear.setUTCHours(0, 0, 0, 0);
  15. var startOfThisYear = startOfUTCISOWeek(fourthOfJanuaryOfThisYear);
  16. if (date.getTime() >= startOfNextYear.getTime()) {
  17. return year + 1;
  18. } else if (date.getTime() >= startOfThisYear.getTime()) {
  19. return year;
  20. } else {
  21. return year - 1;
  22. }
  23. }