diff --git a/PH.WorkingDaysAndTime/Directory.Build.props b/PH.WorkingDaysAndTime/Directory.Build.props
index e7000c9..12edab8 100644
--- a/PH.WorkingDaysAndTime/Directory.Build.props
+++ b/PH.WorkingDaysAndTime/Directory.Build.props
@@ -2,9 +2,9 @@
   <PropertyGroup>
 	<Authors>Paolo Innocenti</Authors>
 	<Copyright>Copyright 2021 (c) Paolo Innocenti - paonath@gmail.com </Copyright>    
-	<AssemblyVersion>2.0.8</AssemblyVersion>
-    <FileVersion>2.0.8</FileVersion>
-    <Version>2.0.8</Version>
+	<AssemblyVersion>2.0.9</AssemblyVersion>
+    <FileVersion>2.0.9</FileVersion>
+    <Version>2.0.9</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)'=='Debug'">
diff --git a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility.UnitTest/MultiCalculatedHolidaysTest.cs b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility.UnitTest/MultiCalculatedHolidaysTest.cs
new file mode 100644
index 0000000..075a796
--- /dev/null
+++ b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility.UnitTest/MultiCalculatedHolidaysTest.cs
@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using PH.WorkingDaysAndTimeUtility.Configuration;
+using Xunit;
+
+namespace PH.WorkingDaysAndTimeUtility.UnitTest
+{
+    public class MultiCalculatedHolidaysTest : BaseTest
+    {
+        [Fact]
+        public void TestWorkingOnSaturdayIfOdd()
+        {
+            var wts1 = new WorkTimeSpan() { Start = new TimeSpan(9, 0, 0), End = new TimeSpan(13, 0, 0)  };
+
+            var wts2 = new WorkTimeSpan() { Start = new TimeSpan(14, 0, 0), End = new TimeSpan(18, 0, 0) };
+            var wts  = new List<WorkTimeSpan>() { wts1, wts2 };
+            var week = new WeekDaySpan()
+            {
+                WorkDays = new Dictionary<DayOfWeek, WorkDaySpan>()
+                {
+                    {DayOfWeek.Monday, new WorkDaySpan() {TimeSpans = wts }}
+                    ,
+                    {DayOfWeek.Tuesday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Wednesday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Thursday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Friday, new WorkDaySpan() {TimeSpans = wts}} ,
+                    {DayOfWeek.Saturday, new WorkDaySpan() {TimeSpans = wts}}
+                }
+            };
+
+            var italians = GetItalianHolidaysWithNoEasterMonday();
+            italians.Add(new EasterMonday());
+            italians.Add(new HoliDay(1, 12));
+            italians.Add(new WorkingOnSaturdayIfOdd());
+
+            var utility = new PH.WorkingDaysAndTimeUtility.WorkingDaysAndTimeUtility(week, italians);
+
+            var aSaturday = new DateTime(2021, 8, 7);
+            var t1        = utility.IsAWorkDay(aSaturday);
+            var t2        = utility.IsAWorkDay(aSaturday.AddDays(7));
+            var t3        = utility.IsAWorkDay(aSaturday.AddDays(14));
+            var t4        = utility.IsAWorkDay(aSaturday.AddDays(21));
+
+            Assert.False(t1);
+            Assert.False(t3);
+            Assert.True(t2);
+            Assert.True(t4);
+
+        }
+    }
+
+    public class WorkingOnSaturdayIfOdd : MultiCalculatedHoliDay
+    {
+        public WorkingOnSaturdayIfOdd() : base(0, 0)
+        {
+        }
+
+        public override Type GetHolyDayType() => typeof(WorkingOnSaturdayIfOdd);
+
+        /// <summary>Calculates the list of MultiCalculatedHoliDays for the given year.</summary>
+        /// <param name="year">The year.</param>
+        /// <returns></returns>
+        public override List<DateTime> CalculateList(int year)
+        {
+            var         first        = new DateTime(year, 1, 1, 0, 0, 0);
+            var         last         = new DateTime(year +1, 1, 1, 0, 0, 0);
+            CultureInfo myCI         = new CultureInfo("it-IT");
+            var         baseHolidays = new List<DateTime>();
+            while (first < last)
+            {
+                if (first.DayOfWeek == DayOfWeek.Saturday)
+                {
+                    var weekNumber = myCI.Calendar.GetWeekOfYear(first, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
+                    if (weekNumber % 2 == 0)
+                    {
+                        baseHolidays.Add(first);
+                    }
+                }
+
+                first = first.AddDays(1);
+            }
+
+            return baseHolidays;
+        }
+    }
+}
\ No newline at end of file
diff --git a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/Configuration/HoliDay.cs b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/Configuration/HoliDay.cs
index 1be230c..b68dd04 100644
--- a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/Configuration/HoliDay.cs
+++ b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/Configuration/HoliDay.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Newtonsoft.Json;
 using PH.WorkingDaysAndTimeUtility.Converter;
 
@@ -150,6 +151,33 @@ public string AHolyDayToString()
         }
     }
 
+    public abstract class MultiCalculatedHoliDay : CalculatedHoliDay
+    {
+        
+        /// <summary>
+        /// It returns an instance of the data by year provided
+        /// </summary>
+        /// <param name="year">year provided</param>
+        /// <returns>DateTime</returns>
+        [Obsolete("For MultiCalculatedHoliDay use 'List<DateTime> CalculateList(int year);'", true)]
+#pragma warning disable CS0809 // Obsolete member overrides non-obsolete member
+        public override DateTime Calculate(int year)
+#pragma warning restore CS0809 // Obsolete member overrides non-obsolete member
+        {
+            throw new
+                NotSupportedException($"For {nameof(MultiCalculatedHoliDay)} use 'List<DateTime> CalculateList(int year);'");
+        }
+
+        /// <summary>Calculates the list of MultiCalculatedHoliDays for the given year.</summary>
+        /// <param name="year">The year.</param>
+        /// <returns></returns>
+        public abstract List<DateTime> CalculateList(int year);
+
+        protected MultiCalculatedHoliDay(int day, int mont) : base(day, mont)
+        {
+        }
+    }
+
     /// <summary>
     /// Holiday: a non-working day.
     /// 
diff --git a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/PH.WorkingDaysAndTimeUtility.csproj b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/PH.WorkingDaysAndTimeUtility.csproj
index 98e57fc..9bd0ec5 100644
--- a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/PH.WorkingDaysAndTimeUtility.csproj
+++ b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/PH.WorkingDaysAndTimeUtility.csproj
@@ -15,14 +15,13 @@
 
       The application works only counting the dates forward and it is assumed that the date entered as the first parameter is a working day.</Description>
     <PackageReleaseNotes>
-      Fix time splitting bugs.
-      Now able to determine if given date is holyday
+      Now able to add multi-calculated holidays to your configuration
     </PackageReleaseNotes>
 
     
-    <PackageTags>work-days,DateTime,work-hours,work-minutes,work-DateTime,holiday,timespan, time-slices</PackageTags>
+    <PackageTags>work-days,DateTime,work-hours,work-minutes,work-DateTime,holiday,timespan, time-slices, holiday</PackageTags>
 
-    <PackageVersion>2.0.8</PackageVersion>
+    <PackageVersion>2.0.9</PackageVersion>
     <Authors>Paolo Innocenti</Authors>
     <Copyright>Copyright PH 2021 (c) paonath@gmail.com. All rights reserved.</Copyright>
     <RepositoryUrl>https://github.com/paonath/PH.WorkingDaysAndTime</RepositoryUrl>
diff --git a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/WorkingDaysAndTimeUtility.cs b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/WorkingDaysAndTimeUtility.cs
index 0e9b3cf..5f41634 100644
--- a/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/WorkingDaysAndTimeUtility.cs
+++ b/PH.WorkingDaysAndTime/PH.WorkingDaysAndTimeUtility/WorkingDaysAndTimeUtility.cs
@@ -898,7 +898,15 @@ private List<DateTime> CalculateDaysForExclusions(int year)
             {
                 try
                 {
-                    r.Add(day.Calculate(year));
+                    if (day is MultiCalculatedHoliDay multi)
+                    {
+                        r.AddRange(multi.CalculateList(year));
+                    }
+                    else
+                    {
+                        r.Add(day.Calculate(year));    
+                    }
+                    
                 }
                 catch 
                 {
diff --git a/README.md b/README.md
index 2ec920f..142c311 100644
--- a/README.md
+++ b/README.md
@@ -221,6 +221,89 @@ var res = utility.SplitWorkedTimeInFactors(n, e);
 var hours = res.TotalDuration.TotalHours;
 ```
 
+**Implements a multi-calculated holiday**
+```c#
+public class WorkingOnSaturdayIfOdd : MultiCalculatedHoliDay
+    {
+        public WorkingOnSaturdayIfOdd() : base(0, 0)
+        {
+        }
+
+        public override Type GetHolyDayType() => typeof(WorkingOnSaturdayIfOdd);
+
+        /// <summary>Calculates the list of MultiCalculatedHoliDays for the given year.</summary>
+        /// <param name="year">The year.</param>
+        /// <returns></returns>
+        public override List<DateTime> CalculateList(int year)
+        {
+            var         first        = new DateTime(year, 1, 1, 0, 0, 0);
+            var         last         = new DateTime(year +1, 1, 1, 0, 0, 0);
+            CultureInfo myCI         = new CultureInfo("it-IT");
+            var         baseHolidays = new List<DateTime>();
+            while (first < last)
+            {
+                if (first.DayOfWeek == DayOfWeek.Saturday)
+                {
+                    var weekNumber = myCI.Calendar.GetWeekOfYear(first, CalendarWeekRule.FirstDay, DayOfWeek.Monday);
+                    if (weekNumber % 2 == 0)
+                    {
+                        baseHolidays.Add(first);
+                    }
+                }
+
+                first = first.AddDays(1);
+            }
+
+            return baseHolidays;
+        }
+    }
+//...
+[Fact]
+        public void TestWorkingOnSaturdayIfOdd()
+        {
+            var wts1 = new WorkTimeSpan() { Start = new TimeSpan(9, 0, 0), End = new TimeSpan(13, 0, 0)  };
+
+            var wts2 = new WorkTimeSpan() { Start = new TimeSpan(14, 0, 0), End = new TimeSpan(18, 0, 0) };
+            var wts  = new List<WorkTimeSpan>() { wts1, wts2 };
+            var week = new WeekDaySpan()
+            {
+                WorkDays = new Dictionary<DayOfWeek, WorkDaySpan>()
+                {
+                    {DayOfWeek.Monday, new WorkDaySpan() {TimeSpans = wts }}
+                    ,
+                    {DayOfWeek.Tuesday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Wednesday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Thursday, new WorkDaySpan() {TimeSpans = wts}}
+                    ,
+                    {DayOfWeek.Friday, new WorkDaySpan() {TimeSpans = wts}} ,
+                    {DayOfWeek.Saturday, new WorkDaySpan() {TimeSpans = wts}}
+                }
+            };
+
+            var italians = GetItalianHolidaysWithNoEasterMonday();
+            italians.Add(new EasterMonday());
+            italians.Add(new HoliDay(1, 12));
+            italians.Add(new WorkingOnSaturdayIfOdd());
+
+            var utility = new PH.WorkingDaysAndTimeUtility.WorkingDaysAndTimeUtility(week, italians);
+
+            var aSaturday = new DateTime(2021, 8, 7);
+            var t1        = utility.IsAWorkDay(aSaturday);
+            var t2        = utility.IsAWorkDay(aSaturday.AddDays(7));
+            var t3        = utility.IsAWorkDay(aSaturday.AddDays(14));
+            var t4        = utility.IsAWorkDay(aSaturday.AddDays(21));
+
+            Assert.False(t1);
+            Assert.False(t3);
+            Assert.True(t2);
+            Assert.True(t4);
+
+        }
+    }
+```
+
 ## Code Configuration Examples
 
 **Use of WorkingDaysConfig**