diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7094d4..618f1de 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
  - Added a method for converting 24 hour to 12 hour format
  - Added a method for determining if a culture uses 24 hour format
+ - Added math util method for mod
 
 ## [9.8.0] - 2019-09-03
 ### Added
diff --git a/ICD.Common.Utils.Tests/MathUtilsTest.cs b/ICD.Common.Utils.Tests/MathUtilsTest.cs
index ebf3280..74129a1 100644
--- a/ICD.Common.Utils.Tests/MathUtilsTest.cs
+++ b/ICD.Common.Utils.Tests/MathUtilsTest.cs
@@ -1,14 +1,13 @@
 using NUnit.Framework;
 using System.Collections.Generic;
 using System.Linq;
-using ICD.Common.Properties;
 
 namespace ICD.Common.Utils.Tests
 {
-	[TestFixture, UsedImplicitly]
+	[TestFixture]
 	public sealed class MathUtilsTest
 	{
-		[Test, UsedImplicitly]
+		[Test]
 		public void ClampTest()
 		{
 			Assert.AreEqual(MathUtils.Clamp(-10, 0, 0), 0);
@@ -24,7 +23,7 @@ namespace ICD.Common.Utils.Tests
 			Assert.AreEqual(MathUtils.Clamp(20, 10, 10), 10);
 		}
 
-		[Test, UsedImplicitly]
+		[Test]
 		public void MapRangeTest()
 		{
 			Assert.AreEqual(5, MathUtils.MapRange(-100, 100, 0, 10, 0));
@@ -40,7 +39,7 @@ namespace ICD.Common.Utils.Tests
 			Assert.AreEqual(100, MathUtils.MapRange(0, 10, 0, 100, 10));
 		}
 
-		[Test, UsedImplicitly]
+		[Test]
 		public void GetRangesTest()
         {
             IEnumerable<int> values = new [] { 1, 3, 5, 6, 7, 8, 9, 10, 12 };
@@ -61,11 +60,21 @@ namespace ICD.Common.Utils.Tests
             Assert.AreEqual(12, ranges[3][1]);
         }
 
-        [Test, UsedImplicitly]
+        [Test]
         public void RoundToNearestTest()
         {
             IEnumerable<int> values = new [] { 0, 15, 30, 45 };
             Assert.AreEqual(15, MathUtils.RoundToNearest(21, values));
         }
+
+		[TestCase(10, 10, 0)]
+		[TestCase(-10, 10, 0)]
+		[TestCase(9, 3, 0)]
+		[TestCase(3, 2, 1)]
+		[TestCase(-3, 2, 1)]
+		public void ModTest(int value, int mod, int expected)
+		{
+			Assert.AreEqual(expected, MathUtils.Mod(value, mod));
+		}
     }
 }
diff --git a/ICD.Common.Utils/DateTimeUtils.cs b/ICD.Common.Utils/DateTimeUtils.cs
index edcda83..a424ffd 100644
--- a/ICD.Common.Utils/DateTimeUtils.cs
+++ b/ICD.Common.Utils/DateTimeUtils.cs
@@ -9,7 +9,7 @@
 		/// <returns></returns>
 		public static int To12Hour(int hour)
 		{
-			return ((hour + 11) % 12) + 1;
+			return MathUtils.Mod(hour + 11, 12) + 1;
 		}
 	}
 }
diff --git a/ICD.Common.Utils/MathUtils.cs b/ICD.Common.Utils/MathUtils.cs
index 832ccba..ee6ebe5 100644
--- a/ICD.Common.Utils/MathUtils.cs
+++ b/ICD.Common.Utils/MathUtils.cs
@@ -209,5 +209,17 @@ namespace ICD.Common.Utils
 
 			return nearest.Aggregate((x, y) => Math.Abs(x - number) < Math.Abs(y - number) ? x : y);
 		}
+
+		/// <summary>
+		/// Calculates the modulus of the given number.
+		/// </summary>
+		/// <param name="number"></param>
+		/// <param name="mod"></param>
+		/// <returns></returns>
+		public static int Mod(int number, int mod)
+		{
+			int remainder = number % mod;
+			return remainder < 0 ? remainder + mod : remainder;
+		}
 	}
 }