This code works for me: it sets new time for my Win98 box.

use strict;
use Win32::API;

my $GetSystemTime = new Win32::API('kernel32', 'GetSystemTime', 'P', '
+V');
#you can also use GetLocalTime

my $lpSystemtime = pack('S8',0,0,0,0,0,0,0,0);

$GetSystemTime->Call($lpSystemtime);

my ($wYear,$wMonth,$wDayOfWeek,$wDay,$wHour,$wMinute,$wSecond,$wMillis
+econds) = unpack('S8', $lpSystemtime);

print "Actual time is: $wHour:$wMinute:$wSecond\n";

$wHour++;
$wMinute++;
$wSecond++;

$lpSystemtime = pack('S8',$wYear,$wMonth,$wDayOfWeek,$wDay,$wHour,$wMi
+nute,$wSecond,$wMilliseconds);

my $SetSystemTime = new Win32::API('kernel32', 'SetSystemTime', 'P', '
+I');
#you can also use SetLocalTime

if ($SetSystemTime->Call($lpSystemtime)) {

    print "The new time is correctly setted: $wHour:$wMinute:$wSecond\
+n"

} else {

    print "Error setting the time\n"
}
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