Piwik\Site::getMinMaxDateAcrossWebsites PHP Method

    public static function getMinMaxDateAcrossWebsites($siteIds)
    {
        $siteIds = self::getIdSitesFromIdSitesString($siteIds);
        $now = Date::now();
        $minDate = null;
        $maxDate = $now->subDay(1)->getTimestamp();
        foreach ($siteIds as $idsite) {
            // look for 'now' in the website's timezone
            $timezone = Site::getTimezoneFor($idsite);
            $date = Date::adjustForTimezone($now->getTimestamp(), $timezone);
            if ($date > $maxDate) {
                $maxDate = $date;
            }
            // look for the absolute minimum date
            $creationDate = Site::getCreationDateFor($idsite);
            $date = Date::adjustForTimezone(strtotime($creationDate), $timezone);
            if (is_null($minDate) || $date < $minDate) {
                $minDate = $date;
            }
        }
        return array(Date::factory($minDate), Date::factory($maxDate));
    }

 public function getSitesInfo($isWidgetized = false)
 {
     Piwik::checkUserHasSomeViewAccess();
     $displayRevenueColumn = Common::isGoalPluginEnabled();
     $date = Common::getRequestVar('date', 'today');
     $period = Common::getRequestVar('period', 'day');
     $siteIds = APISitesManager::getInstance()->getSitesIdWithAtLeastViewAccess();
     list($minDate, $maxDate) = Site::getMinMaxDateAcrossWebsites($siteIds);
     // overwrites the default Date set in the parent controller
     // Instead of the default current website's local date,
     // we set "today" or "yesterday" based on the default Piwik timezone
     $piwikDefaultTimezone = APISitesManager::getInstance()->getDefaultTimezone();
     if ($period != 'range') {
         $date = $this->getDateParameterInTimezone($date, $piwikDefaultTimezone);
         $this->setDate($date);
         $date = $date->toString();
     }
     $dataTable = APIMultiSites::getInstance()->getAll($period, $date, $segment = false);
     // put data into a form the template will understand better
     $digestableData = array();
     foreach ($siteIds as $idSite) {
         $isEcommerceEnabled = Site::isEcommerceEnabledFor($idSite);
         $digestableData[$idSite] = array('idsite' => $idSite, 'main_url' => Site::getMainUrlFor($idSite), 'name' => Site::getNameFor($idSite), 'visits' => 0, 'pageviews' => 0);
         if ($period != 'range') {
             $digestableData[$idSite]['visits_evolution'] = 0;
             $digestableData[$idSite]['pageviews_evolution'] = 0;
         }
         if ($displayRevenueColumn) {
             $revenueDefault = $isEcommerceEnabled ? 0 : "'-'";
             if ($period != 'range') {
                 $digestableData[$idSite]['revenue_evolution'] = $revenueDefault;
             }
         }
     }
     foreach ($dataTable->getRows() as $row) {
         $idsite = (int) $row->getMetadata('idsite');
         $site =& $digestableData[$idsite];
         $site['visits'] = (int) $row->getColumn('nb_visits');
         $site['pageviews'] = (int) $row->getColumn('nb_pageviews');
         if ($displayRevenueColumn) {
             if ($row->getColumn('revenue') !== false) {
                 $site['revenue'] = $row->getColumn('revenue');
             }
         }
         if ($period != 'range') {
             $site['visits_evolution'] = $row->getColumn('visits_evolution');
             $site['pageviews_evolution'] = $row->getColumn('pageviews_evolution');
             if ($displayRevenueColumn) {
                 $site['revenue_evolution'] = $row->getColumn('revenue_evolution');
             }
         }
     }
     $this->applyPrettyMoney($digestableData);
     $view = new View("@MultiSites/getSitesInfo");
     $view->isWidgetized = $isWidgetized;
     $view->sitesData = array_values($digestableData);
     $view->evolutionBy = $this->evolutionBy;
     $view->period = $period;
     $view->page = $this->page;
     $view->limit = $this->limit;
     $view->orderBy = $this->orderBy;
     $view->order = $this->order;
     $view->totalVisits = $dataTable->getMetadata('total_nb_visits');
     $view->totalRevenue = $dataTable->getMetadata('total_revenue');
     $view->displayRevenueColumn = $displayRevenueColumn;
     $view->totalPageviews = $dataTable->getMetadata('total_nb_pageviews');
     $view->pastTotalVisits = $dataTable->getMetadata('last_period_total_nb_visits');
     $view->totalVisitsEvolution = $dataTable->getMetadata('total_visits_evolution');
     if ($view->totalVisitsEvolution > 0) {
         $view->totalVisitsEvolution = '+' . $view->totalVisitsEvolution;
     }
     if ($period != 'range') {
         $lastPeriod = Period::factory($period, $dataTable->getMetadata('last_period_date'));
         $view->pastPeriodPretty = self::getCalendarPrettyDate($lastPeriod);
     }
     $params = $this->getGraphParamsModified();
     $view->dateSparkline = $period == 'range' ? $date : $params['date'];
     $view->autoRefreshTodayReport = false;
     // if the current date is today, or yesterday,
     // in case the website is set to UTC-12), or today in UTC+14, we refresh the page every 5min
     if (in_array($date, array('today', date('Y-m-d'), 'yesterday', Date::factory('yesterday')->toString('Y-m-d'), Date::factory('now', 'UTC+14')->toString('Y-m-d')))) {
         $view->autoRefreshTodayReport = Config::getInstance()->General['multisites_refresh_after_seconds'];
     }
     $this->setGeneralVariablesView($view);
     $this->setMinDateView($minDate, $view);
     $this->setMaxDateView($maxDate, $view);
     $view->show_sparklines = Config::getInstance()->General['show_multisites_sparklines'];
     return $view->render();
 }