Global Positioning System (GPS) when first developed was only available to the US military. Later civilians were allowed access with Selective Availability (SA) but the GPS signal accuracy was greatly reduced.
May 2nd 2000, on the instructions of President Bill Clinton, the US government turned off its Selective Availability. By “flipping the switch” everyone had access to high accuracy GPS signal. Twenty-four satellites around the globe processed their new orders, and instantly the accuracy of GPS technology improved tenfold. Tens of thousands of GPS receivers around the world had an instant upgrade. Even though there was not a blue switch, for some unknown reason, geocachers refer to this day as Blue Switch Day.
With the availability of accurate GPS signal the world changed forever with the introduction of new technologies that today we take for granted. Gone are the days of the road atlas!
May 3rd 2000 saw the first geocache hidden by Dave Ulmer in Oregon and the beginning of the game that we know today.
In celebration of this Blue Switch Day geocaching first introduced a souvenir in 2017. To obtain your Blue Switch Day 2021 souvenir simply find either a geocache, an Adventure Lab or attend an event anytime between May 2nd to December 31st.