fix New Year calculation when observed crosses year

Fixes #98

v2/cal.go

@@ -94,8 +94,8 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
 		}
 		obsMatch := !obs.IsZero()
 		if obsMatch {
-			_, obsMonth, obsDay := obs.Date()
-			obsMatch = obsMonth == month && obsDay == day
+			obsYear, obsMonth, obsDay := obs.Date()
+			obsMatch = obsYear == year && obsMonth == month && obsDay == day
 		}
 		if actMatch || obsMatch {
 			if c.Cacheable {

v2/cal_business.go

@@ -186,9 +186,10 @@ func (c *BusinessCalendar) WorkdaysInRange(start, end time.Time) int {
 // for the given year and month.
 //
 // The value of n affects the direction of counting:
-//   n > 0: counting begins at the first day of the month.
-//   n == 0: the result is always 0.
-//   n < 0: counting begins at the end of the month.
+//
+//	n > 0: counting begins at the first day of the month.
+//	n == 0: the result is always 0.
+//	n < 0: counting begins at the end of the month.
 func (c *BusinessCalendar) WorkdayN(year int, month time.Month, n int) int {
 	var date time.Time
 	var add int

v2/cal_funcs.go

@@ -16,11 +16,12 @@ func IsWeekend(t time.Time) bool {
 // given time.
 //
 // The value of n affects the direction of counting:
-//   n > 0: the result is the nth occurrence counting forwards from the
-//     given time.
-//   n == 0: the result is always the zero time.
-//   n < 0: the result is the nth occurrence counting backwards from the
-//     given time.
+//
+//	n > 0: the result is the nth occurrence counting forwards from the
+//	  given time.
+//	n == 0: the result is always the zero time.
+//	n < 0: the result is the nth occurrence counting backwards from the
+//	  given time.
 //
 // The given time is considered an occurrence of the weekday; if n == 1 or -1
 // and the given time matches the desired weekday, it will be returned

v2/tests/issue_98_test.go

@@ -0,0 +1,34 @@
+package tests
+
+import (
+	"testing"
+	"time"
+
+	"github.com/rickar/cal/v2"
+	"github.com/rickar/cal/v2/us"
+)
+
+// New Year calculation was not checking that the observed year was correct so
+// 12/31/2022 was treated as a holiday because 12/31/2021 was.
+func TestNewYear2022(t *testing.T) {
+	c := cal.NewBusinessCalendar()
+	c.AddHoliday(us.NewYear)
+
+	tests := []struct {
+		date    time.Time
+		wantAct bool
+		wantObs bool
+	}{
+		{time.Date(2022, 12, 31, 12, 30, 0, 0, time.UTC), false, false},
+		{time.Date(2023, 1, 1, 12, 30, 0, 0, time.UTC), true, false},
+		{time.Date(2023, 1, 2, 12, 30, 0, 0, time.UTC), false, true},
+	}
+
+	for i, test := range tests {
+		gotAct, gotObs, _ := c.IsHoliday(test.date)
+		if gotAct != test.wantAct || gotObs != test.wantObs {
+			t.Errorf("[%d] gotAct: %t, wantAct: %t; gotObs: %t, wantObs: %t", i, gotAct, test.wantAct, gotObs,
+				test.wantObs)
+		}
+	}
+}