function r = fixtime(instclass, r, nb2gga_coef);
% 
% r = fixtime(instclass,  r, nb2gga_coef);
% time correction (to aux times) 
% 
%  [nb2gga_coef] = get_nbddaycoef(instclass, a_path, filebase, yearbase)

dday0 = r.dday - nb2gga_coef(1); 
r.dday = nb2gga_coef(2) + nb2gga_coef(3)*dday0 ;

r.nav.sec_pc_minus_utc = zeros(size(r.dday));  

if (isempty(r.dday))
   error('no data in r.dday (fillnavhdg)')
end
