Heard Island and McDonald Islands - Add HolidayProvider

src/Nager.Date/HolidayProviders/HeardIslandAndMcDonaldIslandsHolidayProvider.cs

@@ -0,0 +1,38 @@
+using Nager.Date.Models;
+using System.Collections.Generic;
+
+namespace Nager.Date.HolidayProviders
+{
+    /// <summary>
+    /// Heard Island and McDonald Islands HolidayProvider
+    /// </summary>
+    internal sealed class HeardIslandAndMcDonaldIslandsHolidayProvider : AbstractHolidayProvider
+    {
+        /// <summary>
+        /// Heard Island and McDonald Islands HolidayProvider
+        /// </summary>
+        public HeardIslandAndMcDonaldIslandsHolidayProvider() : base(CountryCode.HM)
+        {
+        }
+
+        /// <inheritdoc/>
+        protected override IEnumerable<HolidaySpecification> GetHolidaySpecifications(int year)
+        {
+            /*
+            * Heard Island and McDonald Islands has no population therefore no official holidays.
+            */
+
+            var holidaySpecifications = new List<HolidaySpecification>();
+            return holidaySpecifications;
+        }
+
+        /// <inheritdoc/>
+        public override IEnumerable<string> GetSources()
+        {
+            return
+            [
+                "https://en.wikipedia.org/wiki/Heard_Island_and_McDonald_Islands"
+            ];
+        }
+    }
+}

src/Nager.Date/HolidaySystem.cs

@@ -73,6 +73,7 @@ public static class HolidaySystem
                 { CountryCode.GG, new Lazy<IHolidayProvider>(() => new GuernseyHolidayProvider(_catholicProvider))},
                 { CountryCode.GY, new Lazy<IHolidayProvider>(() => new GuyanaHolidayProvider(_catholicProvider))},
                 { CountryCode.HK, new Lazy<IHolidayProvider>(() => new HongKongHolidayProvider(_catholicProvider))},
+                { CountryCode.HM, new Lazy<IHolidayProvider>(() => new HeardIslandAndMcDonaldIslandsHolidayProvider())},
                 { CountryCode.HN, new Lazy<IHolidayProvider>(() => new HondurasHolidayProvider(_catholicProvider))},
                 { CountryCode.HR, new Lazy<IHolidayProvider>(() => new CroatiaHolidayProvider(_catholicProvider))},
                 { CountryCode.HT, new Lazy<IHolidayProvider>(() => new HaitiHolidayProvider(_catholicProvider))},