Procedure

   SpiceDouble jyear_c ( void )

Abstract

   Return the number of seconds in a julian year.

Required_Reading

   None.

Keywords

   CONSTANTS

Brief_I/O

   VARIABLE  I/O              DESCRIPTION
   --------  ---  --------------------------------------------------
   jyear_c    O   The number of seconds/julian year

Detailed_Input

   None.

Detailed_Output

   The function returns the number of seconds per julian
   year.

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

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

Examples

   Suppose you wish to compute the number of julian centuries
   that have elapsed since the ephemeris epoch J1950 (beginning
   of the julian year 1950) at a particular ET epoch.  The
   following lines of code will do the trick.


      century = ( et - unitim_c ( j1950_c(), "JED", "ET" ) );
      century = century / ( 100.0 * jyear_c() );

Restrictions

   None.

Literature_References

   Explanatory Supplement to the Astronomical Almanac.
   Page 8. University Science Books, 20 Edgehill Road,
   Mill Valley, CA 94941

Author_and_Institution

   E.D. Wright     (JPL)
   W.L. Taber      (JPL)

Version

   -CSPICE Version 1.0.0, 08-FEB-1998 (EDW)

Index_Entries

   Number of seconds per julian year

Link to routine jyear_c source file jyear_c.c