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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.import { DAY, WEEK } from "./constants.ts";
const DAYS_PER_WEEK = 7;
enum Day {  Sun,  Mon,  Tue,  Wed,  Thu,  Fri,  Sat,}
/** * Returns the ISO week number of the provided date (1-53). * * @example * ```ts * import { weekOfYear } from "https://deno.land/std@$STD_VERSION/datetime/week_of_year.ts"; * * weekOfYear(new Date("2020-12-28T03:24:00")); // Returns 53 * ``` * * @return Number of the week in year */export function weekOfYear(date: Date): number {  const workingDate = new Date(    Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()),  );
  const day = workingDate.getUTCDay();
  const nearestThursday = workingDate.getUTCDate() +    Day.Thu -    (day === Day.Sun ? DAYS_PER_WEEK : day);
  workingDate.setUTCDate(nearestThursday);
  // Get first day of year  const yearStart = new Date(Date.UTC(workingDate.getUTCFullYear(), 0, 1));
  // return the calculated full weeks to nearest Thursday  return Math.ceil((workingDate.getTime() - yearStart.getTime() + DAY) / WEEK);}