Cosmic Calendar

The Cosmic Calendar is the calendar by which the galaxy operates. Mentioned in the Metroid: Zero Mission manual, it is said that two events occurred in the Cosmic Calendar, the forming of the Galactic Federation in 2003, and the attack on the Space Research Vessel Marina and the events leading up to Samus Aran's Zero Mission in the Year 20X5. The Metroid Prime Trilogy manual refers to the calendar as the Cosmo Dating System.

In the manuals for the original Metroid, as well as Metroid II: Return of Samus, the forming of the Federation took place in 2000 "of the cosmos," and the Cosmic Calendar is not mentioned.

Official data

Metroid: Zero Mission related quotes

"In the year 2003 of the Cosmic Calendar, representatives from the many different planets in the galaxy established a congress called the Galactic Federation, and an age of prosperity began."

"In the year 20X5 of the Cosmic Calendar, a terrible incident occurred."

Metroid: Samus Returns Japanese website

Cosmic Calendar 20X5

The "Metroids", floating lifeforms discovered on planet SR388, were attempted to be used as a biological weapon by the Space Pirates, utilizing their dangerous power in their plan to conquer the galaxy. Bounty Hunter Samus Aran descended into the Space Pirate stronghold on planet Zebes and succeeded at destroying Mother Brain.

However, it was discovered that deep under the surface of Planet SR388 many Metroids remain.

The Galactic Federation has since ordered the extermination of the Metroids.

Trivia

• "Cosmic Calendar" is an oxymoron, as years are commonly counted by a specific planet orbiting its host star and months are counted by the planet's moon orbiting around it, but the Metroid games are set throughout the galaxy.