Galactic Stardate

When archives must outlast planets, they stop trusting planets as their clock. That is the civic logic behind Galactic Stardate.

Galactic Stardate is the deep-time calendar used for cross-Concordant history. Unlike local calendars, it is anchored to galactic rotational phase, not planetary orbital years.

Core Principle

• Primary unit: rotational fraction of the Milky Way analog's full core-orbit cycle.
• Reference frame: fixed against galactic center drift markers maintained by Survey Corps astrometric arrays.
• Reasoning: planetary-year systems vary by world and species; galactic rotation provides a shared, non-local baseline.

Practical Use

• Galactic Stardate is used for events spanning many worlds, long migrations, and pre-contact archaeology.
• UCSD remains the standard for day-to-day records and mission logs.
• Archives may cite both forms together, with UCSD for local sequencing and Galactic Stardate for deep chronology.

Canonical Rule

When chronology must remain stable across multiple planets or species timescales, Galactic Stardate is the authoritative timestamp.

Local calendars remain the norm for the worlds themselves; see Solar Time and Local Calendars.