From 30dae389e34db1497088f8cd7d48774e1c0e7932 Mon Sep 17 00:00:00 2001
From: Ryu Hoshino <hoshino.ryu@enechain.co.jp>
Date: Mon, 2 Dec 2024 14:17:38 +0900
Subject: [PATCH 1/2] Fix: Handle Mountain Day Holiday Correctly in Jp

---
 v2/jp/jp_holidays.go | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/v2/jp/jp_holidays.go b/v2/jp/jp_holidays.go
index 4131727..f2a4a17 100644
--- a/v2/jp/jp_holidays.go
+++ b/v2/jp/jp_holidays.go
@@ -4,10 +4,11 @@
 package jp
 
 import (
-	"github.com/rickar/cal/v2"
-	"github.com/rickar/cal/v2/aa"
 	"math"
 	"time"
+
+	"github.com/rickar/cal/v2"
+	"github.com/rickar/cal/v2/aa"
 )
 
 var (
@@ -141,12 +142,24 @@ var (
 
 	// MountainDay represents Mountain Day on 11-August
 	MountainDay = &cal.Holiday{
-		Name:      "Mountain Day",
-		Type:      cal.ObservancePublic,
-		Month:     time.August,
-		Day:       11,
-		Observed:  weekendAlt,
-		Func:      cal.CalcDayOfMonth,
+		Name:     "Mountain Day",
+		Type:     cal.ObservancePublic,
+		Month:    time.August,
+		Day:      11,
+		Observed: weekendAlt,
+		Func: func(h *cal.Holiday, year int) time.Time {
+			switch year {
+			case 2020:
+				// Mountain Day is observed on August 10 in 2020
+				return time.Date(year, time.August, 10, 0, 0, 0, 0, time.Local)
+			case 2021:
+				// Mountain Day is observed on August 8 from 2021
+				return time.Date(year, time.August, 8, 0, 0, 0, 0, time.Local)
+			default:
+				// For all other years, Mountain Day is observed on August 11
+				return time.Date(year, time.August, 11, 0, 0, 0, 0, time.Local)
+			}
+		},
 		StartYear: 2016,
 	}
 

From 384ff9e8574b81679ac606fb93694a3db0f4bdd9 Mon Sep 17 00:00:00 2001
From: Ryu Hoshino <hoshino.ryu@enechain.co.jp>
Date: Wed, 4 Dec 2024 10:10:39 +0900
Subject: [PATCH 2/2] fix test

---
 v2/jp/jp_holidays_test.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/v2/jp/jp_holidays_test.go b/v2/jp/jp_holidays_test.go
index 689bee8..f913ad1 100644
--- a/v2/jp/jp_holidays_test.go
+++ b/v2/jp/jp_holidays_test.go
@@ -3,9 +3,10 @@
 package jp
 
 import (
-	"github.com/rickar/cal/v2"
 	"testing"
 	"time"
+
+	"github.com/rickar/cal/v2"
 )
 
 func d(y, m, d int) time.Time {
@@ -130,9 +131,11 @@ func TestHolidays(t *testing.T) {
 		{MountainDay, 2017, d(2017, 8, 11), d(2017, 8, 11)},
 		{MountainDay, 2018, d(2018, 8, 11), d(2018, 8, 11)},
 		{MountainDay, 2019, d(2019, 8, 11), d(2019, 8, 12)},
-		{MountainDay, 2020, d(2020, 8, 11), d(2020, 8, 11)},
-		{MountainDay, 2021, d(2021, 8, 11), d(2021, 8, 11)},
+		{MountainDay, 2020, d(2020, 8, 10), d(2020, 8, 10)},
+		{MountainDay, 2021, d(2021, 8, 8), d(2021, 8, 9)},
 		{MountainDay, 2022, d(2022, 8, 11), d(2022, 8, 11)},
+		{MountainDay, 2023, d(2023, 8, 11), d(2023, 8, 11)},
+		{MountainDay, 2024, d(2024, 8, 11), d(2024, 8, 12)},
 
 		{RespectForTheAgedDay, 2015, d(2015, 9, 21), d(2015, 9, 21)},
 		{RespectForTheAgedDay, 2016, d(2016, 9, 19), d(2016, 9, 19)},