Day 2 solution in C#

src/Timer.cs

@@ -0,0 +1,47 @@
+using System.Diagnostics;
+
+namespace aoc2021
+{
+    internal class Timer : IDisposable
+    {
+        private readonly Stopwatch stopwatch = Stopwatch.StartNew();
+        public void Dispose()
+        {
+            stopwatch.Stop();
+            var (elapsed, unit) = ConvertElapsedToHumanReadable();
+            Logger.Log($"Took {elapsed:N1}{unit}");
+        }
+
+        public (double elapsed, string unit) ConvertElapsedToHumanReadable()
+        {
+            return ConvertElapsedToHumanReadable(stopwatch.ElapsedTicks, Stopwatch.Frequency);
+        }
+
+        public static (double elapsed, string unit) ConvertElapsedToHumanReadable(double ticks, long frequency)
+        {
+            var elapsed = 1.0d * ticks / frequency;
+            var unit = "s";
+            if (elapsed < 0.001)
+            {
+                elapsed *= 1e+6;
+                unit = "us";
+            }
+            else if (elapsed < 1)
+            {
+                elapsed *= 1000;
+                unit = "ms";
+            }
+            else if (elapsed < 60)
+            {
+                unit = "s";
+            }
+            else if (elapsed < 60 * 60)
+            {
+                elapsed /= 60;
+                unit = "m";
+            }
+
+            return (elapsed, unit);
+        }
+    }
+}