Show Time Stamp on Bash History

Ever wondered when did I execute the command? You could add a time stamp in front of each command you executed.

echo 'export HISTTIMEFORMAT=" %F %T "' >> ~/.bashrc
source ~/.bashrc

You will see time stamps on your commands when you execute history next time.
The result will look like:

1013 2013-05-09 14:47:44 vim scripts_for_Distance_Matrix.txt
1014 2013-05-09 14:48:01 R < scripts_for_Distance_Matrix.txt --no-save