Computer Clock Updater

The National Institute of Standards and Technology maintains a collection of atomic clocks that are so accurate that the best of them won't gain or lose a second in 20 million years. You can set your computer clock to the NIST standard with a free downloadable program from its site, available for both Windows and Macintosh users. It takes only a few seconds to download—give or take. Once you download the program, use the "Query Server" menu to update your clock and/or set the program to update automatically at regular intervals of your choosing. You have to be connected to the Internet for the update to work.