How to configure time zone using POSIX format in Centos 5?

I was in process of developing a new script to configure a time zone. After some study I got the unix utility /usr/bin/tzselect to get the user inputs. Now I am able to configure the time zone depending on the user inputs except for the POSIX format.

root >/usr/bin/tzselect 
Please identify a location so that time zone rules can be set correctly.
Please select a continent or ocean.
 1) Africa
 2) Americas
 3) Antarctica
 4) Arctic Ocean
 5) Asia
 6) Atlantic Ocean
 7) Australia
 8) Europe
 9) Indian Ocean
10) Pacific Ocean
11) none - I want to specify the time zone using the Posix TZ format.
#? 2
Please select a country.
 1) Anguilla             27) Honduras
 2) Antigua & Barbuda         28) Jamaica
 3) Argentina             29) Martinique
 4) Aruba             30) Mexico
 5) Bahamas             31) Montserrat
 6) Barbados             32) Netherlands Antilles
 7) Belize             33) Nicaragua
 8) Bolivia             34) Panama
 9) Brazil             35) Paraguay
10) Canada             36) Peru
11) Cayman Islands         37) Puerto Rico
12) Chile             38) St Barthelemy
13) Colombia             39) St Kitts & Nevis
14) Costa Rica             40) St Lucia
15) Cuba             41) St Martin (French part)
16) Dominica             42) St Pierre & Miquelon
17) Dominican Republic         43) St Vincent
18) Ecuador             44) Suriname
19) El Salvador             45) Trinidad & Tobago
20) French Guiana         46) Turks & Caicos Is
21) Greenland             47) United States
22) Grenada             48) Uruguay
23) Guadeloupe             49) Venezuela
24) Guatemala             50) Virgin Islands (UK)
25) Guyana             51) Virgin Islands (US)
26) Haiti
#? 2

The following information has been given:

    Antigua & Barbuda

Therefore TZ='America/Antigua' will be used.
Local time is now:    Wed Nov 28 04:00:31 AST 2012.
Universal Time is now:    Wed Nov 28 08:00:31 UTC 2012.
Is the above information OK?
1) Yes
2) No
#? y
Please enter 1 for Yes, or 2 for No.
#? 1

You can make this change permanent for yourself by appending the line
    TZ='America/Antigua'; export TZ
to the file '.profile' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you
can use the /usr/bin/tzselect command in shell scripts:
America/Antigua
root >

This utility /usr/bin/tzselect provide an option to give a POSIX time format. Suppose if a user provide the posix format as GMT-14 then how do I configure the time zone? I am using Centos 5.

PERL has an embedded db that might help: cgi - Get time zone abbreviation using POSIX (Perl) - Stack Overflow

The Olson DB escribed: tz database - Wikipedia, the free encyclopedia

Noe GMT-14 is UTC + 14 hours is UTC - 10 hours is, according to the database:

List of tz database time zones - Wikipedia, the free encyclopedia
it is HST, so you would set TZ to HTC-10 or something like that. POSIX offset sign is backward of TZ: GMT/UTC standards reversed in timezone standards (and PHP, and wordpress, and Unix/Posix) | Stef's Blog

Of course, you might be off a day!

$ ( echo $TZ ; date ; TZ=GMT-14 ; date )
EST5EDT
Wed Dec 19 12:19:32 EST 2012
Thu Dec 20 07:19:32 GMT 2012
$ ( echo $TZ ; date ; TZ=GMT+14 ; date )
EST5EDT
Wed Dec 19 12:20:14 EST 2012
Wed Dec 19 03:20:14 GMT 2012
$ ( echo $TZ ; date ; TZ=GMT14 ; date )
EST5EDT
Wed Dec 19 12:21:18 EST 2012
Wed Dec 19 03:21:18 GMT 2012
$ ( echo $TZ ; date ; TZ=Pacific/Kiritimati ; date )
EST5EDT
Wed Dec 19 12:26:52 EST 2012
Wed Dec 19 17:26:52 Pacific/Kiritimati 2012
$ ( echo $TZ ; date ; TZ=Pacific/Kiritimati-14 ; date )
EST5EDT
Wed Dec 19 12:27:50 EST 2012
Thu Dec 20 07:27:50 Pacific/Kiritimati 2012
$ 

So, TZ sets the visible name, for which there should be a table of 3 place capital letter codes for every offset, but apparently there is not. Using more than 3 places may work some places.