fastercsv of zip code and time zone made into hash

I have a csv of zip code and time zone like so.

array_zipcodes =
00501,U,Holtsville,D,Suffolk,36103,New York,NY,
36,5380,631,Eastern,-5.0,Y, 40.813078, -73.046388
00501,U,I R S Service Center,N,Suffolk,36103,New York,NY,
36,5380,631,Eastern,-5.0,Y, 40.813078, -73.046388
00544,U,Holtsville,D,Suffolk,36103,New York,NY,
36,5380,631,Eastern,-5.0,Y, 40.813223, -73.049288
00544,U,IRS Service Center,N,Suffolk,36103,New York,NY,
36,5380,631,Eastern,-5.0,Y, 40.813223, -73.049288'

I want a hash like

zip_to_UTC = [
00501 => -5,
00544 => -5,]

Then I am interacting with salesforce API to grab customer data and
figure out all their zip codes and put them through this to generate
SQL update statement.

for your pleasure if you want to know how to grab salesforce data. I
made my own hash for State to UTC offset, but I need it to be zip to
UTC as that is more accurate. Any help very much appreciated.

require 'rubygems'
require 'activerecord'
require 'activesalesforce'
require 'fastercsv' ## this is what I have so far.

FIELDS = [ "ZIPCode","UTC"]

csv_data ="5-digit Commercial.csv")

class Account < ActiveRecord::Base
# end