Abstract

   CSPICE_TYEAR returns the double precision value of the number
   of seconds in a tropical year: 31556925.9747

I/O

   Given:

      No input required.

   the call:

      tyear = cspice_tyear()

   returns:

      tyear    a double precision scalar, the number of seconds per tropical
               year.

               help, tyear
                  DOUBLE = Scalar

               This value is taken from the 1992 Explanatory Supplement to the
               Astronomical Almanac.

Parameters

   None.

Examples

   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

   1) The following code example returns the double precision value of
      the number of seconds in a tropical year, and prints it out.

      Example code begins here.


      PRO tyear_ex1

         ;;
         ;; Print the double precision value of seconds in a tropical
         ;; year.
         ;;
         print, FORMAT='("Seconds per tropical year: ",F20.8)', $
                cspice_tyear()

      END


      When this program was executed on a Mac/Intel/IDL8.x/64-bit
      platform, the output was:


      Seconds per tropical year:    31556925.97470000

Particulars

   The tropical year is often used as a fundamental unit
   of time when dealing with older ephemeris data. For this
   reason its value in terms of ephemeris seconds is
   recorded in this function.

Exceptions

   Error free.

Files

   None.

Restrictions

   None.

Required_Reading

   ICY.REQ
   TIME.REQ

Literature_References

   [1]  P. Kenneth Seidelmann (Ed.), "Explanatory Supplement to the
        Astronomical Almanac," p 80, University Science Books, 1992.

Author_and_Institution

   J. Diaz del Rio     (ODC Space)
   E.D. Wright         (JPL)

Version

   -Icy Version 1.0.1, 10-AUG-2021 (JDR)

       Corrected the value given for the number of seconds in the
       tropical year in the -Abstract section.

       Edited the -Examples section to comply with NAIF standard. Added
       example's problem statement and reformatted example's output.

       Added -Parameters, -Exceptions, -Files, -Restrictions,
       -Literature_References and -Author_and_Institution sections, and
       completed -Particulars section.

       Removed reference to the routine's corresponding CSPICE header from
       -Abstract section.

       Added argument's type and size information in the -I/O section.

   -Icy Version 1.0.0, 16-JUN-2003 (EDW)

Index_Entries

   Number of seconds per tropical year