How to output day of the year out of a netcdf file?

[Chi Ding <chi@xxxxxxxxx>]

Hi ferret users
     I need to output ascii data out of netcdf
files and the time values needs to be in "day of
the year" format, say "221.24".
     When I use commands like this
list/clobber/noheader/file="test2.txt"/t="01-JUN-2003":"01-JUL-2003" 
air_temperature,
the output is like
01-JUN-2003 00:00 / 244:   9.19
01-JUN-2003 01:00 / 245:   8.47
01-JUN-2003 02:00 / 246:   8.33
01-JUN-2003 03:00 / 247:   8.41
01-JUN-2003 04:00 / 248:   8.12
01-JUN-2003 05:00 / 249:   7.75
01-JUN-2003 06:00 / 250:   7.41
01-JUN-2003 07:00 / 251:   7.56
01-JUN-2003 08:00 / 252:   7.44
01-JUN-2003 09:00 / 253:   7.27
01-JUN-2003 10:00 / 254:   7.15
01-JUN-2003 11:00 / 255:   7.27
01-JUN-2003 12:00 / 256:   7.70

         I'm wondering how to print the time in day of the year  using 
ferret?
Or is there other way to convert "01-JUN-2003 01:00" to day of the year?
Ferret or other languages are all ok.
    Thanks a lot, Ding