We can now parse atoms

timecmd.bat

@@ -0,0 +1,23 @@
+@echo off
+
+set start=%time%
+
+:: runs your command
+%*
+
+set end=%time%
+set options="tokens=1-4 delims=:.,"
+for /f %options% %%a in ("%start%") do set start_h=%%a&set /a start_m=100%%b %% 100&set /a start_s=100%%c %% 100&set /a start_ms=100%%d %% 100
+for /f %options% %%a in ("%end%") do set end_h=%%a&set /a end_m=100%%b %% 100&set /a end_s=100%%c %% 100&set /a end_ms=100%%d %% 100
+
+set /a hours=%end_h%-%start_h%
+set /a mins=%end_m%-%start_m%
+set /a secs=%end_s%-%start_s%
+set /a ms=%end_ms%-%start_ms%
+if %ms% lss 0 set /a secs = %secs% - 1 & set /a ms = 100%ms%
+if %secs% lss 0 set /a mins = %mins% - 1 & set /a secs = 60%secs%
+if 1%ms% lss 100 set ms=0%ms%
+
+echo [finished in %secs%.%ms%s]
+
+exit /b %errorlevel%