diff --git a/CourseApp.Tests/PersonAgeCalculatorTests.cs b/CourseApp.Tests/PersonAgeCalculatorTests.cs
new file mode 100644
index 00000000..cb414d34
--- /dev/null
+++ b/CourseApp.Tests/PersonAgeCalculatorTests.cs
@@ -0,0 +1,21 @@
+namespace CourseApp.Tests
+{
+    using System;
+    using Xunit;
+
+    public class PersonAgeCalculatorTests
+    {
+        [Theory]
+        [InlineData(new[] { 2003, 5, 20 }, new[] { 2021, 5, 20 }, "You are 18th years.")]
+        [InlineData(new[] { 2003, 5, 20 }, new[] { 2021, 11, 10 }, "You are 18 years, 5 months and 23 days")]
+        [InlineData(new[] { 2003, 5, 20 }, new[] { 2022, 5, 3 }, "You are 18 years, 11 months and 14 days")]
+        public void CalculatingAPersonsAge(int[] born, int[] end, string exp)
+        {
+            var mike = new PersonAgeCalculator();
+
+            var res = mike.CalculatingAge(new DateTime(born[0], born[1], born[2]), new DateTime(end[0], end[1], end[2]));
+
+            Assert.Equal(exp, res);
+        }
+    }
+}
\ No newline at end of file
diff --git a/CourseApp/PersonAgeCalculator.cs b/CourseApp/PersonAgeCalculator.cs
new file mode 100644
index 00000000..51535099
--- /dev/null
+++ b/CourseApp/PersonAgeCalculator.cs
@@ -0,0 +1,36 @@
+namespace CourseApp
+{
+    using System;
+
+    public class PersonAgeCalculator
+    {
+        public string CalculatingAge(DateTime born)
+        {
+            return CalculatingAge(born, DateTime.Today);
+        }
+
+        public string CalculatingAge(DateTime born, DateTime end)
+        {
+            DateTime date = DateTime.MinValue.AddTicks(end.Ticks - born.Ticks);
+            if ((date.Day - 2) == 0 && (date.Month - 1) == 0)
+            {
+                return "You are " + (date.Year - 1) + "th" + " years.";
+            }
+            else
+            {
+                return "You are " + (date.Year - 1) + " years, " + (date.Month - 1) + " months and " + (date.Day - 2) + " days";
+            }
+        }
+
+        public void CakeIsALie()
+        {
+            Console.WriteLine(
+                "┈┈┈☆☆☆☆☆☆☆┈┈┈" +
+    "┈┈╭┻┻┻┻┻┻┻┻┻╮┈┈" +
+    "┈┈┃╱╲╱╲╱╲╱╲╱┃┈┈" +
+    "┈╭┻━━━━━━━━━┻╮┈" +
+    "┈┃╱╲╱╲╱╲╱╲╱╲╱┃┈" +
+    "┈┗━━━━━━━━━━━┛┈");
+        }
+    }
+}