diff --git a/AdventOfCode/AOC.Tests/AOC.Tests.csproj b/AdventOfCode/AOC.Tests/AOC.Tests.csproj
index 599b3d1..88c5d56 100644
--- a/AdventOfCode/AOC.Tests/AOC.Tests.csproj
+++ b/AdventOfCode/AOC.Tests/AOC.Tests.csproj
@@ -8,6 +8,13 @@
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
+	<ItemGroup>
+		<None Remove="Y2015\Data\**" />
+		<Content Include="Y2015\Data\**">
+			<CopyToOutputDirectory>Always</CopyToOutputDirectory>
+		</Content>
+	</ItemGroup>
+
 	<ItemGroup>
 		<None Remove="Y2021\Data\**" />
 		<Content Include="Y2021\Data\**">
diff --git a/AdventOfCode/AOC.Tests/Y2015/Data/Day01.dat b/AdventOfCode/AOC.Tests/Y2015/Data/Day01.dat
new file mode 100644
index 0000000..73e014e
--- /dev/null
+++ b/AdventOfCode/AOC.Tests/Y2015/Data/Day01.dat
@@ -0,0 +1 @@
+(((())))()((((((((())()(()))(()((((()(()(((()((()((()(()()()()()))(((()(()((((((((((())(()()((())()(((())))()(()(()((()(()))(()()()()((()((()(((()()(((((((()()())()((((()()(((((()(())()(())((())()()))()(((((((())(()())(()(((())(()))((())))(()((()())))()())((((())))(()(((((()(())(((()()((()((()((((((((((())(()())))))()))())()()((((()()()()()()((((((())())(((()())()((()()(((()()()))(((((()))(((()(()()()(()(()(((())()))(()(((()((())()(()())())))((()()()(()()(((()))(((()((((()(((((()()(()())((()())())(()((((((()(()()))((((()))))())((())()()((()(()))))((((((((()))(()()(((())())(())()((()()()()((()((()((()()(((())))(()((())()((((((((()((()(()()(((())())())))(())())))()((((()))))))())))()()))()())((()())()((()()()))(()()(((()(())((((())())((((((((()()()()())))()()()((((()()))))))()((((()(((()))(()()())))((()()(((()))()()())())(((())((()()(())()()()(((())))))()())((()))()))((())()()())()())()()(()))())))())()))(())((()(())))(()(())(()))))(()(())())(()(())(()(()))))((()())()))()((((()()))))())))()()())((())()((()()()))()(((()(()))))(())()()))(((()())))))))))(((())))()))())()))))()()(((())))))))()(()()(()))((()))))((())))((()((())))())))()()(()))())()(()((()())(()(()()())())(()()))()))))(()())()()))()()()()))(()(()(()))))))()(()))()))()()(()((())(()(())))()(((())(())())))))()(()(()))))()))(()()()(())()(()(())))()))))()()(((((())))))())()())())())()())()))))()))))))))())()()()()()()())))()))((())()))())))()((())()))))()))())))))))())()()()))()()(()((((()(((((((()(())((()())((()()))()))))(())))()()()(())((())()())))(())))(())))(((()()))()(())(((()(()))((())))())()))((((()))())()))))))))()(())())))(()))()(()()))())()()(())())))())()()(()())))()((()())(()(())(())))))))))))))(()))))()))))))()()())(()(((((()(()())))())()))(()))()))(()()))()())(()))())()(())((()()))))))())))())()(((())))(()(()))()()))()(()))))))((()())(()))))))()())))()()))))))))((((((((()()()(()))))))()())))())))()()((())()))((())(())))())())))()()()((()((()(())))())()(())))))))))()())))()()()()()()))()))((())())(()(()))))))(()()))()))(())))()))))))))))))(()))))))))()))))()))()())()))()()))))))()))))((()))))(()))())()(())))(()())((((()())))()))))(()))()(()()(())))))())))))()))))))())))())))))())))())())))())(()))))(())()(())))())()))((()()))))))())))((())))))))())))(())))))()()())))))())))))()))))))()))()()()(()(((()())())())(()))())))))((()(())(()))))))))(())))()()()())())(()))))()()()))()))())())())()(())))()(((()((((())))))))()))))))))))))))))))))((())()())(()))))()()))))))(()()(())())))())))((())))((())))))))))))))()))))()(()))))))())))))()))(()()())(()())))))))))()))))))(())))))()()))()())(((())))()))(()))))))))(())())))())))())())())()()))((())()(())()())()))()())(())(()))))()())))(()(((()))))))()(()())()()()))()))))))))()()()(())()())()(((((()))()())())(()))))()()()(())))())))()((()())))(()))())()(()())())(()))()()))((()()))((()()()()())))(())()))(()(())))((()()))))))))())))))))())()()))))))))))))))))(())()(())(())()())())()))()(()))))())())))))()())()(()))()()(())))(())())))))(()))))))))))))))())())(())(())))(((()))()))))())((())(()))())))))))())))))())))()))()))))))))))))())()))))()))))((()))(())))()(())))(())()))()))())))())))))))()(()())())))()()())))(())))))(()))))))))))))(()))()))()))())))(((()()()(())((()())))()())(((()))(())()))((()()()())))())(())(()))))()(((((())))(()))())())))))))((((()()()))())())()(()(()())))))))))()())())))(())))()())(((()(())())()()))())())))))))((()())((()()(()))(()(())))()))()))(()))(()))()()(()(((())((((()))()(()))((())()(()(()())()(()))()())))))(()))()))())()())))())))(())))((())(()())))))()))(())(()))()())()(()()((()(()))))))()(())(()())(())()))(((())()))(()()(()()()))))(()(())))()))))())))))())(()()()()()()(((())))(()()))()((())(((((()()())))(()))(()))()()))(((())())()(((()()()()))))(()))(())())))()())(()()())())))))))()))))((())))()())(()))(()(()))())))))())(())))))()()())())()))()()(())))(()))(())((((((())(()))(()))())()))(()()(())))()))(()()))()))()(())))(())))((()(()))(())()()())())))(((()()())(())()))))))()(((()(((((()()(((())(())))())()((()))))((()())()(())(((())))(((()((()(()(()))(()()))())(()))(())(())))()))))))((((()))()((((()(()))()))()()))))()(()(()))()(()((()(((()(()()(((()))))()(((()(()(()(((()(()())())()()(()(()())())(()((((())(()))()))(((((()()())(())()((()()())))()()(((()()))()((((((((()(())))())((()))))(())))(()))))((()((((()()(())(((((()))(((((((((((((()())))((((()(((()((())())()))((()))()(()()((()()()()(()()(()(()(((())()(()((((((()((()()((())()((((()((()()(()()())((()()()((()((())()(()(((()((())((((())(()))((()(()))(()())()((((((((()(((((((((((()))(()(((()(()()()((((())((())()())()))(())((())(()))(((()((()(())))(()))))((()()))))((((()(()(()())(()(())((((((((()((((()((()(((((()))())()(()))(()()((()(())(((((()(())()(((((()()))))))()(((())()(()()((((())()((())((()(((())(((()))((()()((((()(())))))((()((((()((()((()(((())((()))(((((((()(((()((((((((())()))((((())(((((()((((((((()(((()((()(((()()(((()((((((()()(()((((((((()()(()(()(())((((()())()))))(((()))((((())((((()())((()(())()((()((((((()(((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\ No newline at end of file
diff --git a/AdventOfCode/AOC.Tests/Y2015/Day01.cs b/AdventOfCode/AOC.Tests/Y2015/Day01.cs
new file mode 100644
index 0000000..a89d303
--- /dev/null
+++ b/AdventOfCode/AOC.Tests/Y2015/Day01.cs
@@ -0,0 +1,82 @@
+using System.Reflection;
+
+namespace AOC.Tests.Y2015
+{
+    [TestFixture, Parallelizable(ParallelScope.All)]
+    public class Day01
+    {
+        protected string GetThisClassName() { return this.GetType().Name; }
+        private string realData;
+
+        [SetUp]
+        public void Setup()
+        {
+            realData = File.ReadAllLines(Path.Combine(TestContext.CurrentContext.TestDirectory, "Y2015", "Data", $"{GetThisClassName()}.dat"))[0];
+        }
+
+        [TestCase("(())", 0)] // Example data
+        [TestCase("()()", 0)] // Example data
+        [TestCase("(((", 3)] // Example data
+        [TestCase("(()(()(", 3)] // Example data
+        [TestCase("))(((((", 3)] // Example data
+        [TestCase("())", -1)] // Example data
+        [TestCase("))(", -1)] // Example data
+        [TestCase(")))", -3)] // Example data
+        [TestCase(")())())", -3)] // Example data
+        [TestCase(null, 232)] // The actual answer
+        public void Part1(string input, int? expected)
+        {
+            var lines = input != null ? input : realData;
+
+            int floorsUp = lines.Count(x => x == '(');
+            int floorsDown = lines.Count(x => x == ')');
+
+            var result = floorsUp - floorsDown;
+
+
+            if (expected != null)
+            {
+                Assert.That(result, Is.EqualTo(expected.Value));
+            }
+
+            Console.WriteLine($"Part 1: {result}");
+        }
+
+        [TestCase(")", 1)] // Example data
+        [TestCase("()())", 5)]
+        [TestCase(null, 1783)] // The actual answer
+        public void Part2(string input, int? expected)
+        {
+            var lines = input != null ? input : realData;
+
+            var currentFloor = 0;
+            int? result = null;
+
+            foreach (var (instruction, index) in lines.WithIndex())
+            {
+                if (instruction is '(')
+                {
+                    currentFloor += 1;
+                }
+                else if (instruction is ')')
+                {
+                    currentFloor -= 1;
+                }
+
+                if (currentFloor is -1)
+                {
+                    // Zero-indexed, so need to increment
+                    result = index + 1;
+                    break;
+                }
+            }
+
+            if (expected != null)
+            {
+                Assert.That(result, Is.EqualTo(expected.Value));
+            }
+
+            Console.WriteLine($"Part 2: {result}");
+        }
+    }
+}
\ No newline at end of file
diff --git a/AdventOfCode/AOC.Tests/Y2015/Tasks/Day01.txt b/AdventOfCode/AOC.Tests/Y2015/Tasks/Day01.txt
new file mode 100644
index 0000000..361b3b5
--- /dev/null
+++ b/AdventOfCode/AOC.Tests/Y2015/Tasks/Day01.txt
@@ -0,0 +1,30 @@
+--- Day 1: Not Quite Lisp ---
+Santa was hoping for a white Christmas, but his weather machine's "snow" function is powered by stars, and he's fresh out! To save Christmas, he needs you to collect fifty stars by December 25th.
+
+Collect stars by helping Santa solve puzzles. Two puzzles will be made available on each day in the Advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants one star. Good luck!
+
+Here's an easy puzzle to warm you up.
+
+Santa is trying to deliver presents in a large apartment building, but he can't find the right floor - the directions he got are a little confusing. He starts on the ground floor (floor 0) and then follows the instructions one character at a time.
+
+An opening parenthesis, (, means he should go up one floor, and a closing parenthesis, ), means he should go down one floor.
+
+The apartment building is very tall, and the basement is very deep; he will never find the top or bottom floors.
+
+For example:
+
+(()) and ()() both result in floor 0.
+((( and (()(()( both result in floor 3.
+))((((( also results in floor 3.
+()) and ))( both result in floor -1 (the first basement level).
+))) and )())()) both result in floor -3.
+To what floor do the instructions take Santa?
+
+--- Part Two ---
+Now, given the same instructions, find the position of the first character that causes him to enter the basement (floor -1). The first character in the instructions has position 1, the second character has position 2, and so on.
+
+For example:
+
+) causes him to enter the basement at character position 1.
+()()) causes him to enter the basement at character position 5.
+What is the position of the character that causes Santa to first enter the basement?
\ No newline at end of file