diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index c62a2447e8c67a90541d0bcb0ac9cb437e6dfdb6..3ebfa125bee0c08877ef9903e27ef82bcb526627 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -53,6 +53,16 @@ def months_since(months)
           end
         end
 
+        # Short-hand for months_ago(1)
+        def last_month
+          months_ago(1)
+        end
+
+        # Short-hand for months_since(1)
+        def next_month
+          months_since(1)
+        end
+
         # Returns a new Time representing the "start" of this week (Monday, 0:00)
         def beginning_of_week
           (self - self.wday.days).midnight + 1.day