SOFA Time Scale and Calendar Tools
International Astronomical Union Standards Of Fundamental Astronomy SOFA Time Scale and Calendar Tools Software version 18 Document revision 1.61 Version for Fortran programming language http://www.iausofa.org 2021 April 18 MEMBERS OF THE IAU SOFA BOARD (2021) John Bangert United States Naval Observatory (retired) Steven Bell Her Majesty’s Nautical Almanac Office Nicole Capitaine Paris Observatory Maria Davis United States Naval Observatory (IERS) Micka¨el Gastineau Paris Observatory, IMCCE Catherine Hohenkerk Her Majesty’s Nautical Almanac Office (chair, retired) Li Jinling Shanghai Astronomical Observatory Zinovy Malkin Pulkovo Observatory, St Petersburg Jeffrey Percival University of Wisconsin Wendy Puatua United States Naval Observatory Scott Ransom National Radio Astronomy Observatory Nick Stamatakos United States Naval Observatory Patrick Wallace RAL Space (retired) Toni Wilmot Her Majesty’s Nautical Almanac Office (trainee) Past Members Wim Brouw University of Groningen Mark Calabretta Australia Telescope National Facility William Folkner Jet Propulsion Laboratory Anne-Marie Gontier Paris Observatory George Hobbs Australia Telescope National Facility George Kaplan United States Naval Observatory Brian Luzum United States Naval Observatory Dennis McCarthy United States Naval Observatory Skip Newhall Jet Propulsion Laboratory Jin Wen-Jing Shanghai Observatory © Copyright 2010-21 International Astronomical Union. All Rights Reserved. Reproduction, adaptation, or translation without prior written permission is prohibited, except as al- lowed under the copyright laws. CONTENTS iii Contents 1 Preliminaries 1 1.1 Introduction ....................................... 1 1.2 Quick start ....................................... 1 1.3 The SOFA time and date routines .......................... 1 1.4 Intended audience ................................... 2 1.5 A simple example: UTC to TT ............................ 2 1.6 Abbreviations ...................................... 3 2 Times and dates 4 2.1 Timekeeping basics ..................................
[Show full text]