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.

Occurrences

The Galactic Tick Day was retroactively calculated to begin on the day Hans Lippershey filed the patent for the telescope on 2 October 1608. The first observance of the holiday was on 29 September 2016, the 235th Galactic Tick Day. Below is a list of further observances:
GTD numberDateRef
1st2 October 1608
235th29 September 2016
236th26 June 2018
237th21 March 2020
238th15 December 2021
239th10 September 2023
240th5 June 2025
241st1 March 2027
242nd24 November 2028
243rd20 August 2030