If/else statements dependent upon time

[Jack]

Hi all,

I am new to GrADS, so maybe that's why I haven't found this on my own yet,
but here's what I'm trying to do:

I want to do a calculation based on an 850 temp map, to forecast surface
temps, that is dependent on the month of the year. Each month has a slightly
different formula than the prior month. Instead of changing the formula in
the script every month, I wanted to use "if/else" statements, where the "if"
is dependent on the month.

I guess my biggest issue now, is getting time identified and used so that it
can be executed by the proper formula (of which there should be 12 in there).

Any help would be greatly appreciated.

Thanks!

Jack