function EDT2GMT(fname)
%converts time variable of EPIC netCDF file from EDT to GMT
nc = netcdf(fname,'write');
tlen = length(nc{'time'});
jd= 4/24 + nc{'time'}(:) + nc{'time2'}(:)/3600/1000/24;
nc{'time'}(1:tlen) = floor(jd);
nc{'time2'}(1:tlen) = (jd - floor(jd)) *3600*1000*24;
close (nc)