If you have a command window open and call the commands manually, you can display a timestamp on each prompt, e.g.
prompt $d $t $_$P$G
It gives you something like:
23.03.2009 15:45:50,77
C:\>
If you have a small batch script that executes your commands, have an empty line before each command, e.g.
(empty line)
myCommand.exe
(next empty line)
myCommand2.exe
You can calculate the execution time for each command by the time information in the prompt. The best would probably be to pipe the output to a textfile for further analysis:
MyBatchFile.bat > output.txt