diff --git a/DavidBerry.Framework/DavidBerry.Framework.Tests/Util/ITimePeriodExtensionsTests.cs b/DavidBerry.Framework/DavidBerry.Framework.Tests/Util/ITimePeriodExtensionsTests.cs
new file mode 100644
index 0000000..cdba95d
--- /dev/null
+++ b/DavidBerry.Framework/DavidBerry.Framework.Tests/Util/ITimePeriodExtensionsTests.cs
@@ -0,0 +1,224 @@
+using DavidBerry.Framework.Util;
+using Shouldly;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace DavidBerry.Framework.Tests.Util;
+
+public class ITimePeriodExtensionsTests
+{
+
+
+
+    private class TimePeriod : ITimePeriod
+    {
+        public DateTime StartTime { get; set; }
+        public DateTime EndTime { get; set; }
+        public TimePeriod(DateTime startTime, DateTime endTime)
+        {
+            StartTime = startTime;
+            EndTime = endTime;
+        }
+    }
+
+
+    [Fact]
+    public void TestOverlapsReturnsTrueWhenPeriodsAreTheSame()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeTrue();
+    }
+
+
+    [Fact]
+    public void TestOverlapsReturnsTrueWhenPeriodOneEndsDuringPeriodTwo()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T14:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T12:00:00"), DateTime.Parse("2024-10-18T16:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeTrue();
+    }
+
+
+
+    [Fact]
+    public void TestOverlapsReturnsTrueWhenPeriodTwoEndsDuringPeriodOne()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T14:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T09:00:00"), DateTime.Parse("2024-10-18T12:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeTrue();
+    }
+
+
+    [Fact]
+    public void TestOverlapsReturnFalseWhenPeriodOneIsBeforePeriodTwo()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T14:00:00"), DateTime.Parse("2024-10-18T17:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeFalse();
+    }
+
+
+
+    [Fact]
+    public void TestOverlapsReturnFalseWhenPeriodTwoIsBeforePeriodOne()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T09:00:00"), DateTime.Parse("2024-10-18T10:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeFalse();
+    }
+
+
+
+    [Fact]
+    public void TestOverlapsReturnFalseWhenPeriodTwoStartsWhenPeriodOneEndse()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T13:00:00"), DateTime.Parse("2024-10-18T15:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeFalse();
+    }
+
+
+    [Fact]
+    public void TestOverlapsReturnFalseWhenPeriodOneStartsWhenPeriodTwoEndse()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T09:00:00"), DateTime.Parse("2024-10-18T11:00:00"));
+
+        // Act
+        bool overlaps = period1.Overlaps(period2); // Should be true
+
+        // Assert
+        overlaps.ShouldBeFalse();
+    }
+
+
+    [Fact]
+    public void TestContainsResturnsTrueWhenDateTimeIsWithinPeriod()
+    {
+        // Arrange
+        var period = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var dateTime = DateTime.Parse("2024-10-18T12:00:00");
+
+        // Act
+        bool contains = period.Contains(dateTime); // Should be true
+
+        // Assert
+        contains.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void TestContainsResturnsFalseWhenDateTimeIsOutsidePeriod()
+    {
+        // Arrange
+        var period = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+        var dateTime = DateTime.Parse("2024-10-18T14:00:00");
+
+        // Act
+        bool contains = period.Contains(dateTime); // Should be true
+
+        // Assert
+        contains.ShouldBeFalse();
+    }
+
+    [Fact]
+    public void TestDurationReturnsCorrectTimeSpan()
+    {
+        // Arrange
+        var period = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T13:30:00"));
+
+        // Act
+        TimeSpan duration = period.Duration(); // Should be 2 hours and 30 minutes
+
+        // Assert
+        duration.ShouldBe(TimeSpan.FromHours(2.5));
+    }
+
+    [Fact]
+    public void TestIsInsideReturnsTrueWhenPeriodTwoInsidePeriodOne()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T16:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T12:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+
+        // Act
+        bool isInside = period2.IsInside(period1); // Should be true
+
+        // Assert
+        isInside.ShouldBeTrue();
+    }
+
+
+
+    [Fact]
+    public void TestIsInsideReturnsFalseWhenPeriodOneEncompassesPeriodTwo()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T16:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T12:00:00"), DateTime.Parse("2024-10-18T13:00:00"));
+
+        // Act
+        bool isInside = period1.IsInside(period2); // Should be false
+
+        // Assert
+        isInside.ShouldBeFalse();
+    }
+
+
+    [Fact]
+    public void TestIsInsideReturnsFalseWhenPeriodsOverlapButAreNotInside()
+    {
+        // Arrange
+        var period1 = new TimePeriod(DateTime.Parse("2024-10-18T11:00:00"), DateTime.Parse("2024-10-18T14:00:00"));
+        var period2 = new TimePeriod(DateTime.Parse("2024-10-18T12:00:00"), DateTime.Parse("2024-10-18T16:00:00"));
+
+        // Act
+        bool overlaps = period1.IsInside(period2); // Should be False
+
+        // Assert
+        overlaps.ShouldBeFalse();
+    }
+
+
+}
\ No newline at end of file
diff --git a/DavidBerry.Framework/DavidBerry.Framework/Util/ITimePeriod.cs b/DavidBerry.Framework/DavidBerry.Framework/Util/ITimePeriod.cs
new file mode 100644
index 0000000..b9c8a90
--- /dev/null
+++ b/DavidBerry.Framework/DavidBerry.Framework/Util/ITimePeriod.cs
@@ -0,0 +1,45 @@
+using Microsoft.EntityFrameworkCore.Diagnostics;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DavidBerry.Framework.Util;
+
+public interface ITimePeriod
+{
+
+    public DateTime StartTime { get; }
+
+    public DateTime EndTime { get; }
+
+}
+
+
+
+public static class ITimePeriodExtensions
+{
+
+    public static bool Overlaps(this ITimePeriod period1, ITimePeriod period2)
+    {
+        return period1.StartTime < period2.EndTime && period2.StartTime < period1.EndTime;
+    }
+
+    public static bool Contains(this ITimePeriod period, DateTime dateTime)
+    {
+        return period.StartTime <= dateTime && dateTime <= period.EndTime;
+    }
+
+    public static TimeSpan Duration(this ITimePeriod period)
+    {
+        return period.EndTime - period.StartTime;
+    }
+
+    public static bool IsInside(this ITimePeriod innerPeriod, ITimePeriod outerPeriod)
+    {
+        return outerPeriod.StartTime <= innerPeriod.StartTime && innerPeriod.EndTime <= outerPeriod.EndTime;
+    }
+
+
+}
\ No newline at end of file