After you've pasted the above text into the file, press Control-X, Y (to save changes), and then Return (to accept the filename). To make your changes take effect, you need to toggle the time server off and on. The easiest way to do that is to open the Date & Time System Preferences panel, and then disable and eanble the "Set date & time automatically" checkbox on the Date & Time tab. You'll notice here that the server list box on the right contains all of the servers you specified in the configuration file.

Once you've reactivated automatic time updating, you're good to go. You can see how this works by returning to Terminal, and running the following command. (Note that you may have to wait anywhere from one to many minutes for the server information to update before this command works.)

Once set up like this, your machine's clock should always be in sync, even if a given timeserver goes offline. Thanks to reader Kurt Schwehr for today's tip.