#!/usr/bin/perl -w
use strict;
use Time::Local;  #needed for timegm()

my $t = '2010-09-06 15:06:53.512999'; #( it is UTC time )

my $newstring = UTC2LocalString($t);

print "  UTC: $t\n";
print "Local: $newstring\n";

=PRINTS:
  UTC: 2010-09-06 15:06:53.512999
Local: 2010-09-06 08:06:53.512999
=cut

sub UTC2LocalString
{
  my $t = shift;
  my ($datehour, $rest) = split(/:/,$t,2);
  my ($year, $month, $day, $hour) = 
      $datehour =~ /(\d+)-(\d\d)-(\d\d)\s+(\d\d)/;
  
  #  proto: $time = timegm($sec,$min,$hour,$mday,$mon,$year);
  my $epoch = timegm (0,0,$hour,$day,$month-1,$year);
  
  #  proto: ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
  #          localtime(time);
  my ($lyear,$lmonth,$lday,$lhour,$isdst) = 
            (localtime($epoch))[5,4,3,2,-1];
  
  $lyear += 1900;  # year is 1900 based
  $lmonth++;       # month number is zero based
  #print "isdst: $isdst\n"; #debug flag day-light-savings time
  return ( sprintf("%04d-%02d-%02d %02d:%s",
           $lyear,$lmonth,$lday,$lhour,$rest) );
}