Code covered by the BSD License  

Highlights from
Geodetic Toolbox

from Geodetic Toolbox by Mike Craymer
Toolbox for angle, coordinate and date conversions and transformations. Version 2.95.

yr=jd2yr(jd);
function yr=jd2yr(jd);
% JD2YR  Converts Julian date to year and decimal of year.
% . Non-vectorized version. See also CAL2JD, DOY2JD,
%   GPS2JD, JD2CAL, JD2DOW, JD2DOY, JD2GPS, JD2YR.
% Version: 24 Apr 99
% Usage:   yr=jd2yr(jd)
% Input:   jd - Julian date
% Output:  yr - year and decimal of year

% Copyright (c) 2011, Michael R. Craymer
% All rights reserved.
% Email: mike@craymer.com

if nargin ~= 1
  warning('Incorrect number of arguments');
  return;
end
if jd < 0
  warning('Julian date must be greater than or equal to zero');
  return;
end

[iyr,mn,yr] = jd2cal(jd);
jd0 = cal2jd(iyr,1,1);
jd1 = cal2jd(iyr+1,1,1);
yr = iyr + (jd-jd0)/(jd1-jd0);

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