function legal = jed_is_legal ( jed )

%*****************************************************************************80
%
%% jed_is_legal() checks a Julian Ephemeris Date.
%
%  Discussion:
%
%    JED values less than zero will be marked illegal.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    16 June 2012
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real JED, the Julian Ephemeris Date.
%
%  Output:
%
%    logical LEGAL:
%    TRUE: JED is legal;
%    FALSE: JED is illegal.
%
  legal = ( 0.0 <= jed );

  return
end
