diff --git a/AOC.Test/Test2015.cs b/AOC.Test/Test2015.cs
index 6843069..c5a5f28 100644
--- a/AOC.Test/Test2015.cs
+++ b/AOC.Test/Test2015.cs
@@ -11,6 +11,7 @@ public class Test2015
     [DataRow(typeof(Day03), "2081", "2341")]
     // [DataRow(typeof(Day04), "346386", "9958218")]
     [DataRow(typeof(Day05), "258", "53")]
+    // [DataRow(typeof(Day06), "543903", "14687245")]
     public void TestAllDays(Type dayType, string part1, string part2)
     {
         Common.CheckDay(dayType, part1, part2);
@@ -22,6 +23,7 @@ public class Test2015
     [DataRow(typeof(Day03), "2", "11")]
     // [DataRow(typeof(Day04), "609043", "6742839")]
     [DataRow(typeof(Day05), "1", "1")]
+    [DataRow(typeof(Day06), "1000000", "1000000")]
     public void CheckTestInputs(Type dayType, string part1, string part2)
     {
         Day.UseTestInput = true;
diff --git a/AOC2015/Day06.cs b/AOC2015/Day06.cs
index d9baddb..83a5f4b 100644
--- a/AOC2015/Day06.cs
+++ b/AOC2015/Day06.cs
@@ -3,13 +3,105 @@
 /// <summary>
 /// Day 6: <see href="https://adventofcode.com/2015/day/6"/>
 /// </summary>
-public sealed class Day06 : Day
+public sealed partial class Day06 : Day
 {
-    public Day06() : base(2015, 6, "Puzzle Name")
+    [GeneratedRegex(@"(\d+),(\d+) through (\d+),(\d+)")]
+    private static partial Regex Coords();
+
+    private readonly Dictionary<(int x, int y), bool> _lightGrid = new();
+    private readonly Dictionary<(int x, int y), int> _brightnessGrid = new();
+
+    public Day06() : base(2015, 6, "Probably a Fire Hazard")
     {
     }
 
-    public override object Part1() => "";
+    public override object Part1()
+    {
+        foreach (var line in Input)
+        {
+            var d = Coords().Match(line).Groups.Values.Skip(1).Select(v => int.Parse(v.Value)).ToList();
+            int x1 = d[0], y1 = d[1], x2 = d[2], y2 = d[3];
+            int xStart = Math.Min(x1, x2), xEnd = Math.Max(x1, x2), yStart = Math.Min(y1, y2), yEnd = Math.Max(y1, y2);
 
-    public override object Part2() => "";
-}
+            for (var x = xStart; x <= xEnd; x++)
+            {
+                for (var y = yStart; y <= yEnd; y++)
+                {
+                    if (line.StartsWith("toggle"))
+                    {
+                        if (_lightGrid.ContainsKey((x, y)))
+                        {
+                            _lightGrid[(x, y)] = !_lightGrid[(x, y)];
+                        }
+                        else
+                        {
+                            _lightGrid[(x, y)] = true;
+                        }
+                    }
+                    else if (line.StartsWith("turn on"))
+                    {
+                        _lightGrid[(x, y)] = true;
+                    }
+                    else if (line.StartsWith("turn off"))
+                    {
+                        _lightGrid[(x, y)] = false;
+                    }
+                }
+            }
+        }
+
+        return _lightGrid.Count(v => v.Value);
+    }
+
+    public override object Part2()
+    {
+        foreach (var line in Input)
+        {
+            var d = Coords().Match(line).Groups.Values.Skip(1).Select(v => int.Parse(v.Value)).ToList();
+            int x1 = d[0], y1 = d[1], x2 = d[2], y2 = d[3];
+            int xStart = Math.Min(x1, x2), xEnd = Math.Max(x1, x2), yStart = Math.Min(y1, y2), yEnd = Math.Max(y1, y2);
+
+            for (var x = xStart; x <= xEnd; x++)
+            {
+                for (var y = yStart; y <= yEnd; y++)
+                {
+                    if (line.StartsWith("toggle"))
+                    {
+                        if (_brightnessGrid.ContainsKey((x, y)))
+                        {
+                            _brightnessGrid[(x, y)] += 2;
+                        }
+                        else
+                        {
+                            _brightnessGrid[(x, y)] = 2;
+                        }
+                    }
+                    else if (line.StartsWith("turn on"))
+                    {
+                        if (_brightnessGrid.ContainsKey((x, y)))
+                        {
+                            _brightnessGrid[(x, y)]++;
+                        }
+                        else
+                        {
+                            _brightnessGrid[(x, y)] = 1;
+                        }
+                    }
+                    else if (line.StartsWith("turn off"))
+                    {
+                        if (_brightnessGrid.ContainsKey((x, y)) && _brightnessGrid[(x, y)] > 0)
+                        {
+                            _brightnessGrid[(x, y)]--;
+                        }
+                        else
+                        {
+                            _brightnessGrid[(x, y)] = 0;
+                        }
+                    }
+                }
+            }
+        }
+
+        return _brightnessGrid.Sum(v => v.Value);
+    }
+}
\ No newline at end of file
diff --git a/AOC2015/input2015/test06.in b/AOC2015/input2015/test06.in
new file mode 100644
index 0000000..8a28f03
--- /dev/null
+++ b/AOC2015/input2015/test06.in
@@ -0,0 +1 @@
+turn on 0,0 through 999,999