diff --git a/hwe/v_history.php b/hwe/v_history.php
index 1220ec45..ab07c294 100644
--- a/hwe/v_history.php
+++ b/hwe/v_history.php
@@ -28,11 +28,11 @@ if ($serverID !== UniqueConst::$serverID) {
 if($serverID === UniqueConst::$serverID){
   [$currentYear, $currentMonth] = $gameStor->getValuesAsArray(['year', 'month']);
   if($f_year === null || $l_year === null){
-    $f_year = $currentYear;
-    $f_month = $currentMonth - 1;
+    $yearMonth = Util::joinYearMonth($currentYear, $currentMonth) - 1;
+    [$f_year, $f_month] = Util::parseYearMonth($yearMonth);
 
-    $l_year = $currentYear;
-    $l_month = $currentMonth - 1;
+    $l_year = $f_year;
+    $l_month = $f_month;
   }
 }
 else{