1 files changed, 66 insertions, 0 deletions
diff --git a/node_modules/moment/src/lib/units/week-calendar-utils.js b/node_modules/moment/src/lib/units/week-calendar-utils.js
new file mode 100644
index 0000000..be67184
--- /dev/null
+++ b/node_modules/moment/src/lib/units/week-calendar-utils.js
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+import { daysInYear } from './year';
+import { createUTCDate } from '../create/date-from-array';
+
+// start-of-first-week - start-of-year
+function firstWeekOffset(year, dow, doy) {
+    var // first-week day -- which january is always in the first week (4 for iso, 1 for other)
+        fwd = 7 + dow - doy,
+        // first-week day local weekday -- which local weekday is fwd
+        fwdlw = (7 + createUTCDate(year, 0, fwd).getUTCDay() - dow) % 7;
+
+    return -fwdlw + fwd - 1;
+}
+
+// https://en.wikipedia.org/wiki/ISO_week_date#Calculating_a_date_given_the_year.2C_week_number_and_weekday
+export function dayOfYearFromWeeks(year, week, weekday, dow, doy) {
+    var localWeekday = (7 + weekday - dow) % 7,
+        weekOffset = firstWeekOffset(year, dow, doy),
+        dayOfYear = 1 + 7 * (week - 1) + localWeekday + weekOffset,
+        resYear,
+        resDayOfYear;
+
+    if (dayOfYear <= 0) {
+        resYear = year - 1;
+        resDayOfYear = daysInYear(resYear) + dayOfYear;
+    } else if (dayOfYear > daysInYear(year)) {
+        resYear = year + 1;
+        resDayOfYear = dayOfYear - daysInYear(year);
+    } else {
+        resYear = year;
+        resDayOfYear = dayOfYear;
+    }
+
+    return {
+        year: resYear,
+        dayOfYear: resDayOfYear,
+    };
+}
+
+export function weekOfYear(mom, dow, doy) {
+    var weekOffset = firstWeekOffset(mom.year(), dow, doy),
+        week = Math.floor((mom.dayOfYear() - weekOffset - 1) / 7) + 1,
+        resWeek,
+        resYear;
+
+    if (week < 1) {
+        resYear = mom.year() - 1;
+        resWeek = week + weeksInYear(resYear, dow, doy);
+    } else if (week > weeksInYear(mom.year(), dow, doy)) {
+        resWeek = week - weeksInYear(mom.year(), dow, doy);
+        resYear = mom.year() + 1;
+    } else {
+        resYear = mom.year();
+        resWeek = week;
+    }
+
+    return {
+        week: resWeek,
+        year: resYear,
+    };
+}
+
+export function weeksInYear(year, dow, doy) {
+    var weekOffset = firstWeekOffset(year, dow, doy),
+        weekOffsetNext = firstWeekOffset(year + 1, dow, doy);
+    return (daysInYear(year) - weekOffset + weekOffsetNext) / 7;
+}