function [datejd]= convertjd(dategc)
%dategd is a 1x6 row vector containing [year month day hour minute second]

a = mod(14 - dategc(2))/12);
y = dategc(1) + 4800 -a;
m = dategc(2) + 12*a - 3;

%absolute julian days
datejdabs = dategc(3) + dategc(4)/24 + mod(153*m +2,5) +365*y + mod(y,4) - mod(y,100) + mod(y,400) - 32045 

%CNES julian days
datejd = datejdabs -2400000.5 - 33282; 


end