1 files changed, 30 insertions, 8 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 95617fb8c2..9e89a33491 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -28,6 +28,13 @@ class DateTime
     end_of_day.to_i - to_i
   end
 
+  # Returns the fraction of a second as a +Rational+
+  #
+  #   DateTime.new(2012, 8, 29, 0, 0, 0.5).subsec # => (1/2)
+  def subsec
+    sec_fraction
+  end
+
   # Returns a new DateTime where one or more of the elements have been changed
   # according to the +options+ parameter. The time options (<tt>:hour</tt>,
   # <tt>:min</tt>, <tt>:sec</tt>) reset cascadingly, so if only the hour is
@@ -143,14 +150,32 @@ class DateTime
   end
   alias :at_end_of_minute :end_of_minute
 
-  # Adjusts DateTime to UTC by adding its offset value; offset is set to 0.
+  # Returns a <tt>Time</tt> instance of the simultaneous time in the system timezone.
+  def localtime(utc_offset = nil)
+    utc = new_offset(0)
+
+    Time.utc(
+      utc.year, utc.month, utc.day,
+      utc.hour, utc.min, utc.sec + utc.sec_fraction
+    ).getlocal(utc_offset)
+  end
+  alias_method :getlocal, :localtime
+
+  # Returns a <tt>Time</tt> instance of the simultaneous time in the UTC timezone.
   #
   #   DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24))     # => Mon, 21 Feb 2005 10:11:12 -0600
-  #   DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc # => Mon, 21 Feb 2005 16:11:12 +0000
+  #   DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc # => Mon, 21 Feb 2005 16:11:12 UTC
   def utc
-    new_offset(0)
+    utc = new_offset(0)
+
+    Time.utc(
+      utc.year, utc.month, utc.day,
+      utc.hour, utc.min, utc.sec + utc.sec_fraction
+    )
   end
+  alias_method :getgm, :utc
   alias_method :getutc, :utc
+  alias_method :gmtime, :utc
 
   # Returns +true+ if <tt>offset == 0</tt>.
   def utc?
@@ -165,13 +190,10 @@ class DateTime
   # Layers additional behavior on DateTime#<=> so that Time and
   # ActiveSupport::TimeWithZone instances can be compared with a DateTime.
   def <=>(other)
-    if other.kind_of?(Infinity)
-      super
-    elsif other.respond_to? :to_datetime
+    if other.respond_to? :to_datetime
       super other.to_datetime rescue nil
     else
-      nil
+      super
     end
   end
-
 end