Thanks to Steve Hankin for pointing me in the right direction. The problem was with my "T" axis - I changed the T axis of my dataset (from time_origin = "01-JAN-0000:00:00:00") to time_origin = "01-JAN-1991:00:00:00" and ferret now works just fine. -- Gary Strand strandwg@ncar.ucar.edu http://www.cgd.ucar.edu/ccr/gary