Untitled1.ps1

Add-Type @'

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace Einstein.Scraps {

    public static class UserInput {

        [DllImport("user32.dll", SetLastError=false)]
        private static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

        [StructLayout(LayoutKind.Sequential)]
        private struct LASTINPUTINFO {
            public uint cbSize;
            public int dwTime;
        }

        public static DateTime LastInput {
            get {

                DateTime bootTime = 
DateTime.UtcNow.AddMilliseconds(-Environment.TickCount);
                DateTime lastInput = 
bootTime.AddMilliseconds(LastInputTicks);
                return lastInput;
            }
        }

        public static TimeSpan IdleTime {
            get {
                return DateTime.UtcNow.Subtract(LastInput);
            }
        }

        public static int LastInputTicks {
            get {

                LASTINPUTINFO lii = new LASTINPUTINFO();
                lii.cbSize = (uint)Marshal.SizeOf(typeof(LASTINPUTINFO));

                GetLastInputInfo(ref lii);

                return lii.dwTime;

            }
        }

    }

}

'@

for ( $i = 0; $i -lt 10; $i++ ) {

    [Einstein.Scraps.UserInput]::LastInput.ToLocalTime()

    Start-Sleep -Seconds 5}