CDO

Hallo,

I have a verys hort question,,
I have several daily data from MERRA, 20 years.
I concatenate the data using cdo
cdo cat *.nc final.nc or cdo mergetime *.nc final.nc

The results is wrong, I got this error:

• NOTE: Coordinates out of order or missing on axis time at subscript 428
• NOTE: A dummy axis of subscripts will be used

Any idea how to solve this issue? especially issue related a non-standard axis (in the CF standard the coordinate values always need to be monotonic)
thank you.