Galactic Tick Day


Galactic Tick Day is an awareness and education day that celebrates the movement of the Solar System around the Milky Way galaxy.
The day occurs at a regular interval of 1.7361 years, which is called a galactic tick. The interval is derived from one centi-arcsecond of a galactic year, which is the Solar System's roughly 225-million-year trip around the Galactic Center. One galactic tick is only about 0.00000077 percent of a full galactic year.

Galactic Tick Day

The first Galactic Tick Day took place one galactic tick after Hans Lippershey filed the patent for the telescope on October 2, 1608. The first observance of the holiday was on September 29, 2016, the 235th Galactic Tick Day. Below is a list of further observances:
GTD numberDateSource
235thSeptember 29, 2016
236thJune 26, 2018
237thMarch 21, 2020
238thDecember 15, 2021