The -ftime option calls either
-ftime1 or -ftime2 options.
The -ftime2 option is newer and will become the
default in newer versions of wgrib2. The -ftime2 option
fixes some problems in describing climatologies of monthly means (averages of averages)
or any nested statistical processing operators. The
-ftime2 option is fully recursize while the older
-ftime1 attempted and failed to bypass the recursion.
Along with the change to -ftime2, the
The -set_ftime, -set_ave options are being replaced
$ wgrib2 grib2.polar -ftime2
1.1:0:24 hour fcst
1.2:0:24 hour fcst