1 files changed, 20 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/duration.rb b/activesupport/lib/active_support/duration.rb
index 87b6407038..1db0ca51ae 100644
--- a/activesupport/lib/active_support/duration.rb
+++ b/activesupport/lib/active_support/duration.rb
@@ -81,6 +81,18 @@ module ActiveSupport
       to_i
     end
 
+    # Flattens all the +parts+ of the duration, and returns a
+    # new duration object.
+    def flatten
+      Duration.new(@value, flatten_parts)
+    end
+
+    # Flattens all the +parts+ of this duration.
+    def flatten!
+      @parts = flatten_parts
+      self
+    end
+
     protected
 
       def sum(sign, time = ::Time.current) #:nodoc:
@@ -97,6 +109,14 @@ module ActiveSupport
         end
       end
 
+      def flatten_parts
+        @parts.inject({}) do |result, (name, value)|
+          result[name] ||= 0
+          result[name] += value
+          result
+        end.to_a
+      end
+
     private
 
       def method_missing(method, *args, &block) #:nodoc: