v0.0.268 added WeekStart() and WeekEnd()

timeext/calendarweek.go

@@ -0,0 +1,28 @@
+package timeext
+
+import "time"
+
+func WeekStart(year, week int) time.Time {
+
+	// https://stackoverflow.com/a/52303730/1761622
+
+	// Start from the middle of the year:
+	t := time.Date(year, 7, 1, 0, 0, 0, 0, time.UTC)
+
+	// Roll back to Monday:
+	if wd := t.Weekday(); wd == time.Sunday {
+		t = t.AddDate(0, 0, -6)
+	} else {
+		t = t.AddDate(0, 0, -int(wd)+1)
+	}
+
+	// Difference in weeks:
+	_, w := t.ISOWeek()
+	t = t.AddDate(0, 0, (week-w)*7)
+
+	return t
+}
+
+func WeekEnd(year, week int) time.Time {
+	return WeekStart(year, week).AddDate(0, 0, 7).Add(time.Duration(-1))
+}