Catalog price rule doesn't apply overnight and possible incorrect time zone

Question

Every time I update Magento I have got this probem: I have to manually applicate the catalog price rule, otherwise they don't work.

I have done the following changes:
File app/Mage.php:

date_default_timezone_set('Europe/Rome');//Instead of UTC

File Mage/CatalogRule/Model/Action/Index/Refresh.php(local copy and none):

$timestamp = $coreDate->gmtTimestamp('Today');

with this line:

$timestamp = Mage::app()->getLocale()->date(null, null, null, true)->get(Zend_Date::TIMESTAMP);

Source: https://stackoverflow.com/questions/25280095/magento-catalog-price-rule-disappears-at-night

Reading this question: Catalog price rule from today does not apply

The time zone set inSystem/Configuration/Genral/Locale options is correct, but if I run this script:

include('app/Mage.php');
Mage::app('admin');

echo date('Ymd His', Mage::getModel('core/date')->gmtTimestamp('today'));

it output 2015-11-07 23:00:00 instead of 2015-11-08 11:19:ss, basically a gap of twelve hours.

Cron Job Setting

File: /app/code/core/Mage/CatalogRule/etc/congif.xml

<jobs>
    <catalogrule_apply_all>
        <schedule>
            <cron_expr>0 1 * * *</cron_expr>
        </schedule>
        <run>
            <model>catalogrule/observer::dailyCatalogUpdate</model>
        </run>
    </catalogrule_apply_all>
</jobs>

File /app/code/core/Mage/Catalog/etc/config.xml

<jobs>
    <catalog_product_index_price_reindex_all>
        <schedule>
            <cron_expr>0 2 * * *</cron_expr>
        </schedule>
        <run>
            <model>catalog/observer::reindexProductPrices</model>
        </run>
    </catalog_product_index_price_reindex_all>
</jobs>

Value in cronjob setting:
EDIT
Using this:

date("Y-m-d H:i:s", Mage::getModel('core/date')->timestamp(time()));

it outputs the time without considering the daylight save, basically one hour in advance

EDIT 2
Reverting the changes in app/Mage.php: has solved the daylight save problem