Unification Day is a semi-fan-made, semi-canon holiday based in the No Man’s Sky simulation.

https://nomanssky.fandom.com/wiki/Unification_Day

Excerpt from a Distress Beacon at a Crashed Ship:

The logs reveal that the pilot was celebrating a festival known as ‘Unification Day’. Groups of similar minds, unable to meet but attempting to find one another, to claim worlds across time and space. Once a year their various alliances, federations, hubs, and empires united to remember all that they were, and could become in time…

This year, Unification Day is being organized by the Galactic Hub. That doesn’t mean it’s being hosted in our space, that just means I’m the one who is responsible for compiling the schedule and reaching out to participants.

So that’s what I’m doing! If you’re a member of a civilization, and you have any bases which would be suitable for hosting a Unification Day activity (minigame, PVP, racing, etc), let me know! I’ll also send you an invite to the Unification Day Council planning server.