diff --git a/lib/holidays.rb b/lib/holidays.rb
index 5eef2f4..717ad1e 100644
--- a/lib/holidays.rb
+++ b/lib/holidays.rb
@@ -48,7 +48,7 @@ module Holidays
   @@holidays_by_month = {}
   @@proc_cache = {}
 
-  WEEKS = {:first => 1, :second => 2, :third => 3, :fourth => 4, :fifth => 5, :last => -1}
+  WEEKS = {:first => 1, :second => 2, :third => 3, :fourth => 4, :fifth => 5, :last => -1, :second_last => -2, :third_last => -3}
   MONTH_LENGTHS = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
   DAY_SYMBOLS = Date::DAYNAMES.collect { |n| n.downcase.intern }
 
@@ -399,6 +399,6 @@ class Date
 
     days = 29 if month == 2 and Date.leap?(year)
       
-    return days - ((Date.civil(year, month, days).wday - wday + 7) % 7)
+    return days - ((Date.civil(year, month, days).wday - wday + 7) % 7) - (7 * (week.abs - 1))
   end
 end
\ No newline at end of file
diff --git a/test/test_date.rb b/test/test_date.rb
index 920fdf2..ef6b372 100644
--- a/test/test_date.rb
+++ b/test/test_date.rb
@@ -39,6 +39,18 @@ class DateTests < Test::Unit::TestCase
     assert_equal 2, Date.calculate_mday(2007, 3, :first, :friday)
     assert_equal 30, Date.calculate_mday(2012, 1, :last, 1)
     assert_equal 29, Date.calculate_mday(2016, 2, :last, 1)
+    
+    # From end of month
+    assert_equal 26, Date.calculate_mday(2009, 8, -1, :wednesday)
+    assert_equal 19, Date.calculate_mday(2009, 8, -2, :wednesday)
+    assert_equal 12, Date.calculate_mday(2009, 8, -3, :wednesday)
+    
+    assert_equal 13, Date.calculate_mday(2008, 8, -3, :wednesday)
+    assert_equal 12, Date.calculate_mday(2009, 8, -3, :wednesday)
+    assert_equal 11, Date.calculate_mday(2010, 8, -3, :wednesday)
+    assert_equal 17, Date.calculate_mday(2011, 8, -3, :wednesday)
+    assert_equal 15, Date.calculate_mday(2012, 8, -3, :wednesday)
+    assert_equal 14, Date.calculate_mday(2013, 8, -3, :wednesday)
   end
 
   def test_mday_allows_integers_or_symbols