diff --git a/src/mibew/libs/common/datetime.php b/src/mibew/libs/common/datetime.php
index 1881b08b..f5de0ca6 100644
--- a/src/mibew/libs/common/datetime.php
+++ b/src/mibew/libs/common/datetime.php
@@ -56,11 +56,11 @@ function get_form_date($day, $month)
 	return 0;
 }
 
-function set_form_date($utime, $prefix)
-{
-	global $page;
-	$page["form${prefix}day"] = date("d", $utime);
-	$page["form${prefix}month"] = date("m.y", $utime);
+function set_form_date($utime, $prefix) {
+	return array(
+		"form${prefix}day" => date("d", $utime),
+		"form${prefix}month" => date("m.y", $utime)
+	);
 }
 
 function date_to_text($unixtime)
diff --git a/src/mibew/operator/statistics.php b/src/mibew/operator/statistics.php
index 4196b673..f7759a12 100644
--- a/src/mibew/operator/statistics.php
+++ b/src/mibew/operator/statistics.php
@@ -76,8 +76,11 @@ if (isset($_GET['startday'])) {
 		$end = time() + 24 * 60 * 60;
 	}
 }
-set_form_date($start, "start");
-set_form_date($end - 24 * 60 * 60, "end");
+$page = array_merge(
+	$page,
+	set_form_date($start, "start"),
+	set_form_date($end - 24 * 60 * 60, "end")
+);
 
 if ($start > $end) {
 	$errors[] = getlocal("statistics.wrong.dates");