BY LETTER
BT (Before Tranquility)
BT (also B.T. or b.t.): Before Tranquillity. Any date before the first landing of Terragens on another celestial body, when the Apollo 11 mission achieved touchdown on the Old Earth's Moon. This was July 20, 1969 c.e. or AD in the Gregorian calendar, and Armstrong Day, 0 AT in the later Tranquility Calendar that became standard in Solsys during the Federation Age.
Scrollable Timeline
Orion's Arm Tranquility Calendar Conversion Tool
The Tranquility Calendar mapped to the Gregorian | |
 Image from Steve Bowers | |
| Click for Larger Image | |
Related Articles
Appears in Topics
Development Notes
Text by Stephen Inniss
Initially published on 29 September 2009.
Initially published on 29 September 2009.
Additional Information
