;-------------------------------------------------------------
;+
; NAME:
;       JS2JD
; PURPOSE:
;       Convert from Julian Seconds to Julian Day Number.
; CATEGORY:
; CALLING SEQUENCE:
;       jd = js2jd(js)
; INPUTS:
;       js = Equivalent Julian Second.    in
; KEYWORD PARAMETERS:
; OUTPUTS:
;       jd = Julian Day Number.           out
; COMMON BLOCKS:
; NOTES:
;       Notes: JS are seconds after 2000 Jan 1 0:00.
;       >>>==> Julian Day Number starts at noon. Example:
;       JD of 2450814 is 1997 Dec 31 12:00:00 Wed.
; MODIFICATION HISTORY:
;       R. Sterner, 1994 Oct 13
;
; Copyright (C) 1994, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made.  This
; routine is provided as is without any express or implied warranties
; whatsoever.  Other limitations apply as described in the file disclaimer.txt.
;-
;-------------------------------------------------------------
 
	function js2jd, js, help=hlp
 
	if (n_params(0) lt 1) or keyword_set(hlp) then begin
	  print,' Convert from Julian Seconds to Julian Day Number.'
	  print,' jd = js2jd(js)'
 	  print,'   js = Equivalent Julian Second.    in'
	  print,'   jd = Julian Day Number.           out'
	  print,' Notes: JS are seconds after 2000 Jan 1 0:00.'
	  print,' >>>==> Julian Day Number starts at noon. Example:'
	  print,' JD of 2450814 is 1997 Dec 31 12:00:00 Wed.'
	  return,''
	endif
 
	jd2000 = ymd2jd(2000,1,1) - 0.5d0	; JD at 2000 Jan 1 0:00.
	jd = jd2000 + js/86400d0		; JD for JS.
 
	return, jd
	end