Editing Astronomical system of units (section)

== Astronomical unit of time ==
{{Main|Day}}
The astronomical unit of time is the [[day]], defined as {{val|86400}} [[second]]s. 365.25 days make up one [[Julian year (astronomy)|Julian year]].<ref name="IAU1976B">{{Citation
| editor-last=Müller | editor-first=Edith A.
| editor2-last=Jappel | editor2-first=A.
| year=1977
| title=Proceedings of the Sixteenth General Assembly Grenoble 1976
| series=Transactions of the International Astronomical Union
| section=Report of Joint Meeting of Commissions 4, 8, 31 on the New System of Astronomical Constants
| volume=16B
| pages=52-67
| url=https://archive.org/details/proceedingsofsix0016inte/page/52/
| publisher=D. Reidel
| place=Dordrecht, Holland
| isbn=90-277-0836-3
}}. Refer to subsection "Recommendations to IAU General Assembly, 1976" on pages 58–61 for specific values.</ref> The symbol ''D'' is used in astronomy to refer to this unit.