Merge pull request #271 from bail16/feature/pl-christmas-eve-holiday

PL: Add Christmas Eve (24 Dec) as public holiday from 2025, update holiday logic and tests (AddWorkingDays, holiday detection)

Author: joaomatossilva

src/DateTimeExtensions/WorkingDays/CultureStrategies/PL_PLHolidayStrategy.cs

@@ -26,6 +26,7 @@ public PL_PLHolidayStrategy()
 
             this.InnerHolidays.Add(ChristianHolidays.Christmas);
             this.InnerHolidays.Add(ChristianHolidays.StStephansDay);
+            this.InnerHolidays.Add(ChristmasEveFrom2025);
         }
 
         private static Holiday may3rdConstitutionDay;
@@ -55,5 +56,18 @@ public static Holiday NationalIndependenceDay
                 return nationalIndependenceDay;
             }
         }
+
+        private static Holiday christmasEveFrom2025;
+        public static Holiday ChristmasEveFrom2025
+        {
+            get
+            {
+                if (christmasEveFrom2025 == null)
+                {
+                    christmasEveFrom2025 = new YearDependantHoliday(year => year >= 2025, new FixedHoliday("Christmas Eve", 12, 24));
+                }
+                return christmasEveFrom2025;
+            }
+        }
     }
 }

tests/DateTimeExtensions.Tests/PLHolidaysTests.cs

@@ -0,0 +1,41 @@
+using System;
+using NUnit.Framework;
+using DateTimeExtensions.WorkingDays;
+using DateTimeExtensions.WorkingDays.CultureStrategies;
+
+namespace DateTimeExtensions.Tests
+{
+    [TestFixture]
+    public class PLHolidaysTests
+    {
+        private WorkingDayCultureInfo dateTimeCulture = new WorkingDayCultureInfo("pl-PL");
+
+        [Test]
+        [TestCase(2024, false)]
+        [TestCase(2025, true)]
+        [TestCase(2026, true)]
+        public void ChristmasEve_Is_Holiday_From_2025(int year, bool shouldBeHoliday)
+        {
+            var date = new DateTime(year, 12, 24);
+            Assert.That(dateTimeCulture.IsHoliday(date), Is.EqualTo(shouldBeHoliday), $"Christmas Eve {year} should be a holiday: {shouldBeHoliday}");
+        }
+
+        [Test]
+        public void AddWorkingDays_Skips_ChristmasEve_From_2025()
+        {
+            // 23.12.2025 (Tuesday) + 1 working day = 29.12.2025 (Monday); 24-26.12 are holidays
+            var start = new DateTime(2025, 12, 23);
+            var result = start.AddWorkingDays(1, dateTimeCulture);
+            Assert.That(result, Is.EqualTo(new DateTime(2025, 12, 29)));
+        }
+
+        [Test]
+        public void AddWorkingDays_DoesNotSkip_ChristmasEve_Before_2025()
+        {
+            // 23.12.2024 (Monday) + 1 working day = 24.12.2024 (Tuesday); Christmas Eve is not a holiday
+            var start = new DateTime(2024, 12, 23);
+            var result = start.AddWorkingDays(1, dateTimeCulture);
+            Assert.That(result, Is.EqualTo(new DateTime(2024, 12, 24)));
+        }
+    }
+}