diff --git a/tsg_util/tsg_writeTSGDataNetCDF.m b/tsg_util/tsg_writeTSGDataNetCDF.m
index a215a37d9a7e760e20a37d5a03de2c0c947bf60d..4c49a290f28fe7d3acf2b80bab30f4bb408654b3 100644
--- a/tsg_util/tsg_writeTSGDataNetCDF.m
+++ b/tsg_util/tsg_writeTSGDataNetCDF.m
@@ -110,13 +110,15 @@ for i=1:numel(nca_keys)
   nc.(nca_keys{i}) = tsg.(nca_keys{i});
 end 
 
-% Write measurements (variables)
-% -------------------------------
+% Convert Matlab julian days (datenum) to 1950 reference
+% ------------------------------------------------------
 d = strmatch('DAYD',ncv_keys);
 for i=1:numel(d)
   tsg.(ncv_keys{d(i)}) = datenumToJulian(tsg.(ncv_keys{d(i)}));
 end
 
+% Write measurements (variables)
+% -------------------------------
 for i=1:numel(ncv_keys)
   % display waitbar
   waitbar( i/numel(ncv_keys), wb, ['writing ' ncv_keys{i} ' variable']);