diff --git a/CRM/Contribute/Form/ContributionCharts.php b/CRM/Contribute/Form/ContributionCharts.php
index 666546e0ca81..892b9006f4b8 100644
--- a/CRM/Contribute/Form/ContributionCharts.php
+++ b/CRM/Contribute/Form/ContributionCharts.php
@@ -172,13 +172,15 @@ public function postProcess() {
           $urlParams = "reset=1&force=1&status=1&start={$startDate}&end={$endDate}&test=0";
         }
         elseif ($chartKey == 'by_year') {
+          $year = substr($index, 0, 4);
+          $year = is_numeric($year) ? (int) $year : date('Y');
           if (!empty($config->fiscalYearStart) && ($config->fiscalYearStart['M'] != 1 || $config->fiscalYearStart['d'] != 1)) {
-            $startDate = date('Ymd', mktime(0, 0, 0, $config->fiscalYearStart['M'], $config->fiscalYearStart['d'], substr($index, 0, 4)));
-            $endDate = date('Ymd', mktime(0, 0, 0, $config->fiscalYearStart['M'], $config->fiscalYearStart['d'], (substr($index, 0, 4)) + 1));
+            $startDate = date('Ymd', mktime(0, 0, 0, $config->fiscalYearStart['M'], $config->fiscalYearStart['d'], $year));
+            $endDate = date('Ymd', mktime(0, 0, 0, $config->fiscalYearStart['M'], $config->fiscalYearStart['d'], $year + 1));
           }
           else {
-            $startDate = CRM_Utils_Date::format(['Y' => substr($index, 0, 4)]);
-            $endDate = date('Ymd', mktime(0, 0, 0, 13, 0, substr($index, 0, 4)));
+            $startDate = CRM_Utils_Date::format(['Y' => $year]);
+            $endDate = date('Ymd', mktime(0, 0, 0, 13, 0, $year));
           }
           $urlParams = "reset=1&force=1&status=1&start={$startDate}&end={$endDate}&test=0";
         }