Greece - Fix Labour Day for 2024 (#642)

#640

src/Nager.Date/HolidayProviders/GreeceHolidayProvider.cs

@@ -1,3 +1,4 @@
+using Nager.Date.Extensions;
 using Nager.Date.Models;
 using Nager.Date.ReligiousProviders;
 using System;
@@ -58,13 +59,6 @@ protected override IEnumerable<HolidaySpecification> GetHolidaySpecifications(in
                     HolidayTypes = HolidayTypes.Public
                 },
                 new HolidaySpecification
-                {
-                    Date = new DateTime(year, 5, 1),
-                    EnglishName = "Labour Day",
-                    LocalName = "Εργατική Πρωτομαγιά",
-                    HolidayTypes = HolidayTypes.Public
-                },
-                new HolidaySpecification
                 {
                     Date = new DateTime(year, 8, 15),
                     EnglishName = "Assumption Day",
@@ -106,9 +100,37 @@ protected override IEnumerable<HolidaySpecification> GetHolidaySpecifications(in
                 this._orthodoxProvider.WhitMonday("Δευτέρα Πεντηκοστής", year)
             };
 
+            holidaySpecifications.AddIfNotNull(this.LabourDay(year));
+
             return holidaySpecifications;
         }
 
+        private HolidaySpecification LabourDay(int year)
+        {
+            var englishName = "Labour Day";
+            var localName = "Εργατική Πρωτομαγιά";
+
+            // Government Gazette B' 1406/4.3.2024 - 15102
+            if (year == 2024)
+            {
+                return new HolidaySpecification
+                {
+                    Date = new DateTime(year, 5, 7),
+                    EnglishName = englishName,
+                    LocalName = localName,
+                    HolidayTypes = HolidayTypes.Public
+                };
+            }
+
+            return new HolidaySpecification
+            {
+                Date = new DateTime(year, 5, 1),
+                EnglishName = englishName,
+                LocalName = localName,
+                HolidayTypes = HolidayTypes.Public
+            };
+        }
+
         /// <inheritdoc/>
         public override IEnumerable<string> GetSources()
         {