First, welcome at the Monastery.  There are a couple of issues with your code, but as it's time to go to bed in my local TZ, I hope some other kind monks will point them out :)

Anyhow, if the idea is to convert those dates (with any TZ) into EST, the whole thing can be simplified considerably, because Date::Manip already does most of the magic while parsing the input string... 

#!/usr/bin/perl -w

use strict;
use Date::Manip;

Date_Init("TZ=EST");  # target TZ

# use your filehandle here instead of DATA
while (my $date_anyTZ = <DATA>) {
    chomp $date_anyTZ;
    # get rid of '~' to make date parseable by Date::Manip
    $date_anyTZ =~ tr/~/ /;

    my $date_EST = UnixDate(ParseDate($date_anyTZ), "%Y-%m-%d %H:%M:%S
+ %Z");

    printf "%-24s -->  %s\n", $date_anyTZ, $date_EST;
}

__DATA__
20050526~18:15:06 GMT
20040401~01:12:02 GMT
20060201~00:59:01 GMT
20060401~01:01:01 EST
20040201~10:10:01 -0600
20010901~04:23:05 -0400
20050526~18:15:06 GMT
20040401~01:12:02 GMT
20000101~00:59:01 -0200
19841223~04:22:06 MST

[download]

Prints 

20050526 18:15:06 GMT    -->  2005-05-26 13:15:06 EST
20040401 01:12:02 GMT    -->  2004-03-31 20:12:02 EST
20060201 00:59:01 GMT    -->  2006-01-31 19:59:01 EST
20060401 01:01:01 EST    -->  2006-04-01 01:01:01 EST
20040201 10:10:01 -0600  -->  2004-02-01 11:10:01 EST
20010901 04:23:05 -0400  -->  2001-09-01 03:23:05 EST
20050526 18:15:06 GMT    -->  2005-05-26 13:15:06 EST
20040401 01:12:02 GMT    -->  2004-03-31 20:12:02 EST
20000101 00:59:01 -0200  -->  1999-12-31 21:59:01 EST
19841223 04:22:06 MST    -->  1984-12-23 06:22:06 EST

[download]

which looks OK to me.

In reply to Re: TimeZone Assistance Requested by almut
in thread TimeZone Assistance Requested by Knoperl

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.