Someday aliens will land and all will be fine until we explain our calendar
The Qeng Ho in Deepness in the Sky had the right idea. They traveled from planet to planet in STL ships, and counted time purely in seconds. They had to account for relativity, but nothing else.<p>A short task might take a kilosecond (about 16 minutes), a watch schedule might plan for activities covering a megasecond (close enough to a month for you and me), while a gigasecond is a good chunk of your life (32 years).<p>&quot;Calendar frippery&quot; was left entirely to the civilations they visited. Since individual civilizations rarely lasted long enough to see repeat visits from the same ship, it wasn&#x27;t important for the traders to learn the local calendar in any detail. One of the characters opines that you know you have stayed in port too long when your crew start using the local calendar.