Unity editor script that logs how long it takes for your project to compile and get into play mode

CompileTimeLogger.cs

using System;
using UnityEditor;
using UnityEditor.Compilation;

[InitializeOnLoad]
public static class CompileTimeLogger
{
    private const string CompileStartTimeKey = "CompileStartTime";
    private const string PlayModeTimerKey = "PlayModeStartTime";

    static CompileTimeLogger()
    {
        // Subscribe to compilation events
        CompilationPipeline.compilationStarted += OnCompilationStarted;
        CompilationPipeline.compilationFinished += OnCompilationFinished;

        // Subscribe to Play Mode events
        EditorApplication.playModeStateChanged += OnPlayModeStateChanged;
    }

    // Compilation Timing
    private static void OnCompilationStarted(object o)
    {
        // Save the start time for compilation
        EditorPrefs.SetString(CompileStartTimeKey, DateTime.Now.ToString());
        UnityEngine.Debug.Log($"{o} Compilation started...");
    }

    private static void OnCompilationFinished(object o)
    {
        // Calculate elapsed time using the persisted start time
        if (EditorPrefs.HasKey(CompileStartTimeKey))
        {
            var startTime = DateTime.Parse(EditorPrefs.GetString(CompileStartTimeKey));
            var elapsed = DateTime.Now.Ticks - startTime.Ticks;
            UnityEngine.Debug.Log($"{o} Compilation finished. Time taken: {TimeSpan.FromTicks(elapsed).TotalMilliseconds} ms");
        }
        else
        {
            UnityEngine.Debug.Log("Compilation finished, but start time was not recorded.");
        }
    }

    // Play Mode Timing
    private static void OnPlayModeStateChanged(PlayModeStateChange state)
    {
        switch (state)
        {
            case PlayModeStateChange.ExitingEditMode:
                // Save the current time to persist across domain reloads
                EditorPrefs.SetString(PlayModeTimerKey, DateTime.Now.ToString());
                UnityEngine.Debug.Log("Exiting Edit Mode... Starting Play Mode timer.");
                break;
            case PlayModeStateChange.EnteredPlayMode:
                // Calculate elapsed time using the persisted start time
                if (EditorPrefs.HasKey(PlayModeTimerKey))
                {
                    var startTime = DateTime.Parse(EditorPrefs.GetString(PlayModeTimerKey));
                    var elapsed = DateTime.Now.Ticks - startTime.Ticks;
                    UnityEngine.Debug.Log($"Entered Play Mode. Time taken: {TimeSpan.FromTicks(elapsed).TotalMilliseconds} ms");
                }
                else
                {
                    UnityEngine.Debug.Log("Entered Play Mode, but start time was not recorded.");
                }

                break;
            case PlayModeStateChange.ExitingPlayMode:
                UnityEngine.Debug.Log("Exiting Play Mode...");
                break;
            case PlayModeStateChange.EnteredEditMode:
                UnityEngine.Debug.Log("Entered Edit Mode.");
                break;
        }
    }
}