init

mc_test/node_modules/date-fns/esm/getISOWeeksInYear/index.js

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+import startOfISOWeekYear from "../startOfISOWeekYear/index.js";
+import addWeeks from "../addWeeks/index.js";
+import requiredArgs from "../_lib/requiredArgs/index.js";
+var MILLISECONDS_IN_WEEK = 604800000;
+
+/**
+ * @name getISOWeeksInYear
+ * @category ISO Week-Numbering Year Helpers
+ * @summary Get the number of weeks in an ISO week-numbering year of the given date.
+ *
+ * @description
+ * Get the number of weeks in an ISO week-numbering year of the given date.
+ *
+ * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
+ *
+ * @param {Date|Number} date - the given date
+ * @returns {Number} the number of ISO weeks in a year
+ * @throws {TypeError} 1 argument required
+ *
+ * @example
+ * // How many weeks are in ISO week-numbering year 2015?
+ * const result = getISOWeeksInYear(new Date(2015, 1, 11))
+ * //=> 53
+ */
+export default function getISOWeeksInYear(dirtyDate) {
+  requiredArgs(1, arguments);
+  var thisYear = startOfISOWeekYear(dirtyDate);
+  var nextYear = startOfISOWeekYear(addWeeks(thisYear, 60));
+  var diff = nextYear.valueOf() - thisYear.valueOf();
+  // Round the number of weeks to the nearest integer
+  // because the number of milliseconds in a week is not constant
+  // (e.g. it's different in the week of the daylight saving time clock shift)
+  return Math.round(diff / MILLISECONDS_IN_WEEK);
+}