working with JJAS time period of different years

[Roxy Mathew <rocksea@xxxxxxxxxxxxxxxxx>]

Hi Ferreters, I have a netcdf file with precipitation
from Jan 1998 to Dec 2002 (pentad values).
I want but to work with the JJAS time period only.
Is there any way I can extract the JJAS time period
of all the years to a new netcdf file?
Or is there another way I can process the JJAS months
together?
I tried with the following method but it is not working:

	var=precip[t=01-jun-1998:30-sep-1998]
	save/file=precip_jjas.cdf var
	var=precip[t=01-jun-1999:30-sep-1999]
	save/append/file=precip_jjas.cdf var

Thanks for any help :) Cheers, Roxy

EES, Hokkaido University
Sapporo, Japan