1 files changed, 12 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index d93c1148c4..5c351c21c6 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -7,6 +7,11 @@ module ActiveSupport #:nodoc:
       module Calculations
         def self.included(base) #:nodoc:
           base.extend ClassMethods
+          
+          base.class_eval do
+            alias_method :compare_without_coercion, :<=>
+            alias_method :<=>, :compare_with_coercion
+          end
         end
 
         module ClassMethods
@@ -91,6 +96,13 @@ module ActiveSupport #:nodoc:
         def utc_offset
           (offset * 86400).to_i
         end
+        
+        # Layers additional behavior on DateTime#<=> so that Time and ActiveSupport::TimeWithZone instances can be compared with a DateTime
+        def compare_with_coercion(other)
+          other = other.comparable_time if other.respond_to?(:comparable_time)
+          other = other.to_datetime unless other.acts_like?(:date)
+          compare_without_coercion(other)
+        end
       end
     end
   end