On September 14, the atomic clocks that enable the Global Positioning System (GPS) struck 1,000,000,000 seconds. GPS was pioneered by the Department of Defense who set the beginning of GPS time on January 6, 1980. It wasn’t until the early 2000’s that GPS became widely available commercially. Before this, the DoD guarded this technology closely and did not allow the system to give civilians precise and accurate readings. This changed when, in 1996, then-President Bill Clinton signed an executive order to turn off Selective Availability (which became effective in 2000). GPS is now used for a wide variety of purposes including military, car navigation, recreation (see: Geocaching) as well as scientific research.