#!/usr/bin/perl -w
use strict;
use Date::Manip;
Date_Init("TZ=EST");    #set TimeZone to Eastern Daylight Savings Time
{
    my $input = $ARGV[0];    #returns filename from command line
    my $thetmz;              #time zone for that line
    my ( $date, $time);      #from file

    chomp $input;                       #strip the carriage return

    sub convertthetmz {
        $datetime = ( "$date" . "$time" )
          ;    #$date and #time from subroutine call and concats them
        $converteddate = ParseDate("$datetime");    #date-time strng
        $converteddate =Date_ConvTZ("$converteddate", $thetmz, "EST" )
          ;    #converts from any tmz to EST
        print("$converteddate~$from~$to\n");
    }

    open( DATAFILE, "$input" )
      || die("Can not open $input:!\n");    #access the file

    while (<DATAFILE>) {
        chomp $_;
        ( $date, $time) = split( "~", $_ );  #split date/time 

        my $testfortmz = substr $time, -3;    #last 4 chars of str
        if ( "$testfortmz" == "-0400" ) {
            $thetmz = "AST";

            convertthetmz( $thetmz, $date, $time, $from, $to );
        }
        elsif ( "$testfortmz" == "-0600" ) {
            $thetmz = "CST";
            convertthetmz( $thetmz, $date, $time, $from, $to );
        }
        elsif ( "$testfortmz" =~ " GMT" ) {
            $thetmz = "GMT";
            convertthetmz( $thetmz, $date, $time, $from, $to );
        }

        else    #this is need to work for some reason
        {
            my $nochangedate;
            $nochangedate = ( ParseDate("$date.$time") );
            print("$nochangedate~$from~$to\n");
        }

    }
    close(DATAFILE);
}