packages/shared/lib/date-fns-utc/getWeekNumber.ts

   1 const MILLISECONDS_IN_WEEK = 604800000;
   2
   3 const getWeekNumber = (date: Date) => {
   4     const start = new Date(date);
   5     start.setUTCHours(0, 0, 0, 0);
   6
   7     const startOfYear = new Date(0);
   8     startOfYear.setUTCFullYear(start.getUTCFullYear());
   9
  10     const diff = Math.max(start.getTime() - startOfYear.getTime(), 0);
  11     const result = Math.round(diff / MILLISECONDS_IN_WEEK) + 1;
  12     return result > 52 ? 1 : result;
  13 };
  14
  15 export default getWeekNumber;