diff --git a/extend/fast/Date.php b/extend/fast/Date.php
index 2b4ad62d..84919255 100644
--- a/extend/fast/Date.php
+++ b/extend/fast/Date.php
@@ -191,13 +191,13 @@ class Date
                 break;
             case 'month':
                 $_timestamp = mktime(0, 0, 0, $month + $offset, 1, $year);
-                $time = $position ? $_timestamp : mktime(23, 59, 59, $month + $offset, cal_days_in_month(CAL_GREGORIAN, date("m", $_timestamp), date("Y", $_timestamp)), $year);
+                $time = $position ? $_timestamp : mktime(23, 59, 59, $month + $offset, self::days_in_month(date("m", $_timestamp), date("Y", $_timestamp)), $year);
                 break;
             case 'quarter':
                 $_month = date("m", mktime(0, 0, 0, (ceil(date('n', mktime(0, 0, 0, $month, $day, $year)) / 3) + $offset) * 3, $day, $year));
                 $time = $position ?
                     mktime(0, 0, 0, 1 + ((ceil(date('n', $baseTime) / 3) + $offset) - 1) * 3, 1, $year) :
-                    mktime(23, 59, 59, (ceil(date('n', $baseTime) / 3) + $offset) * 3, cal_days_in_month(CAL_GREGORIAN, (ceil(date('n', $baseTime) / 3) + $offset) * 3, $year), $year);
+                    mktime(23, 59, 59, (ceil(date('n', $baseTime) / 3) + $offset) * 3, self::days_in_month((ceil(date('n', $baseTime) / 3) + $offset) * 3, $year), $year);
                 break;
             case 'year':
                 $time = $position ? mktime(0, 0, 0, 1, 1, $year + $offset) : mktime(23, 59, 59, 12, 31, $year + $offset);
@@ -208,4 +208,19 @@ class Date
         }
         return $time;
     }
+
+    /**
+     * 获取指定年月拥有的天数
+     * @param int $month
+     * @param int $year
+     * @return false|int|string
+     */
+    public static function days_in_month($month, $year)
+    {
+        if (function_exists("cal_days_in_month")) {
+            return cal_days_in_month(CAL_GREGORIAN, $month, $year);
+        } else {
+            return date('t', mktime(0, 0, 0, $month, 1, $year));
+        }
+    }
 }