ISO 31-1
ISO 31-1 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to "space and time". It was superseded in 2006 by ISO 80000-3. Definitions. Its definitions include: Annex A. Annex A of ISO 31-1 lists units of space and time based on the foot, pound, and second. Annex B. Annex B lists some other non-SI units of space and time, namely the gon, light year, astronomical unit, parsec, tropical year, and gal.