The error message when I run sst step:

 /media/CMIP5/regcm4/SST/tos_Omon_HadGEM2-ES_historical_r1i1p1_195912-200512.nc
 gnmnc_sst : Timestep not in file.:            1
abort: Fortran Abort Called

I have already set to use 360_day calendar.