diff --git a/extend/fast/Date.php b/extend/fast/Date.php
index 8671476d5e117c9f2d7a648c54a82b6a6ab89ab2..d8f7ab467a9b69a6184ec5efe7fc52a2341e013a 100644
--- a/extend/fast/Date.php
+++ b/extend/fast/Date.php
@@ -183,12 +183,14 @@ class Date
                     mktime(23, 59, 59, $month, $day - date("w", mktime(0, 0, 0, $month, $day, $year)) + 7 - 7 * (-$offset), $year);
                 break;
             case 'month':
-                $time = $position ? mktime(0, 0, 0, $month + $offset, 1, $year) : mktime(23, 59, 59, $month + $offset, cal_days_in_month(CAL_GREGORIAN, $month + $offset, $year), $year);
+                $_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);
                 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', mktime(0, 0, 0, $month, $day, $year)) / 3) + $offset) - 1) * 3, 1, $year) :
-                    mktime(23, 59, 59, (ceil(date('n', mktime(0, 0, 0, $month, $day, $year)) / 3) + $offset) * 3, cal_days_in_month(CAL_GREGORIAN, (ceil(date('n', mktime(0, 0, 0, $month, $day, $year)) / 3) + $offset) * 3, $year), $year);
+                    mktime(23, 59, 59, (ceil(date('n', mktime(0, 0, 0, $month, $day, $year)) / 3) + $offset) * 3, cal_days_in_month(CAL_GREGORIAN, $_month, $year), $year);
                 break;
             case 'year':
                 $time = $position ? mktime(0, 0, 0, 1, 1, $year + $offset) : mktime(23, 59, 59, 12, 31, $year + $offset);