1582day.year
The Gregorian Calendar is introduced by Pope Gregory XIII.
In 1582, Pope Gregory XIII promulgated the Gregorian Calendar, correcting the Julian system and standardizing dates across Catholic Europe.
By the late 16th century, the Julian Calendar had drifted ten days out of alignment with the solar year, affecting liturgical observances.
A commission led by Aloysius Lilius proposed omitting ten days and revising leap-year rules for better precision.
Papal bull "Inter gravissimas" decreed the change, advancing the date from October 4 to October 15, 1582.
Catholic states swiftly adopted the new calendar, while Protestant and Orthodox regions transitioned over subsequent centuries.
Today, the Gregorian Calendar is the global civil standard, illustrating its enduring scientific and cultural impact.
1582
Gregorian Calendar
1957day.year
Sputnik 1 becomes the first artificial satellite to orbit the Earth.
Sputnik 1, launched by the Soviet Union in 1957, became the first human-made satellite to orbit Earth.
On October 4, 1957, the Soviet Union successfully placed Sputnik 1 into orbit atop an R-7 rocket, marking the dawn of the Space Age. The 83-kilogram polished metal sphere transmitted radio pulses detectable by amateur radio operators around the globe. Sputnik’s unexpected success shocked the United States and spurred the intensification of the Cold War–era space race. The satellite completed an orbit every 96 minutes, providing valuable data on atmospheric density and radio signal propagation. Its launch demonstrated the feasibility of artificial satellites and led directly to the creation of NASA in 1958. Sputnik’s legacy lives on in the countless satellites and interplanetary missions that followed, forever changing humanity’s relationship with space.
1957
Sputnik 1
1985day.year
The Free Software Foundation is founded.
The Free Software Foundation is established to promote computer user freedoms and open software development.
On October 4, 1985, Richard Stallman founded the Free Software Foundation (FSF) to advocate for users' rights to study, modify, and share software. The FSF spearheaded the GNU Project, aiming to create a fully free Unix-like operating system. It introduced important concepts such as copyleft licensing to ensure software remained free under all downstream licenses. The foundation has played a central role in the open source and free software movements. Its work led to the creation of widely used free software tools and licenses, including the GNU General Public License. The FSF continues to influence software policy, digital rights, and the global software community.
1985
Free Software Foundation
2004day.year
SpaceShipOne wins the Ansari X Prize for private spaceflight.
SpaceShipOne became the first privately funded craft to reach space, winning the Ansari X Prize.
On October 4, 2004, SpaceShipOne successfully achieved a suborbital flight, marking its second journey above 100 kilometers and securing the Ansari X Prize.
Piloted by Mike Melvill, the rocket-powered craft launched atop its White Knight carrier aircraft from the Mojave Desert.
Reaching the edge of space at Mach 3, SpaceShipOne delivered proof-of-concept for privately funded human spaceflight.
The feat completed a two-flight test regimen within 14 days, meeting the competition’s strict requirements.
Winning the $10 million X Prize galvanized a new wave of commercial space ventures and inspired innovative aerospace startups worldwide.
SpaceShipOne's success reshaped the future of space exploration by shifting the frontier from government to private enterprise.
2004
SpaceShipOne