Ruby 1.8.7+ provides to_date/to_datetime, AS just makes them public.

activesupport/lib/active_support/core_ext/time/conversions.rb

@@ -55,31 +55,9 @@ def formatted_offset(colon = true, alternate_utc_string = nil)
     utc? && alternate_utc_string || ActiveSupport::TimeZone.seconds_to_utc_offset(utc_offset, colon)
   end
 
-  # Converts a Time object to a Date, dropping hour, minute, and second precision.
-  #
-  #   my_time = Time.now  # => Mon Nov 12 22:59:51 -0500 2007
-  #   my_time.to_date     # => Mon, 12 Nov 2007
-  #
-  #   your_time = Time.parse("1/13/2009 1:13:03 P.M.")  # => Tue Jan 13 13:13:03 -0500 2009
-  #   your_time.to_date                                 # => Tue, 13 Jan 2009
-  def to_date
-    ::Date.new(year, month, day)
-  end unless method_defined?(:to_date)
-
   # A method to keep Time, Date and DateTime instances interchangeable on conversions.
   # In this case, it simply returns +self+.
   def to_time
     self
   end unless method_defined?(:to_time)
-
-  # Converts a Time instance to a Ruby DateTime instance, preserving UTC offset.
-  #
-  #   my_time = Time.now    # => Mon Nov 12 23:04:21 -0500 2007
-  #   my_time.to_datetime   # => Mon, 12 Nov 2007 23:04:21 -0500
-  #
-  #   your_time = Time.parse("1/13/2009 1:13:03 P.M.")  # => Tue Jan 13 13:13:03 -0500 2009
-  #   your_time.to_datetime                             # => Tue, 13 Jan 2009 13:13:03 -0500
-  def to_datetime
-    ::DateTime.civil(year, month, day, hour, min, sec, Rational(utc_offset, 86400))
-  end unless method_defined?(:to_datetime)
 end

activesupport/test/core_ext/time_ext_test.rb

@@ -533,19 +533,9 @@ def test_custom_date_format
     Time::DATE_FORMATS.delete(:custom)
   end
 
-  def test_to_date
-    assert_equal Date.new(2005, 2, 21), Time.local(2005, 2, 21, 17, 44, 30).to_date
-  end
-
-  def test_to_datetime
-    assert_equal Time.utc(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, 0, 0)
-    with_env_tz 'US/Eastern' do
-      assert_equal Time.local(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, Rational(Time.local(2005, 2, 21, 17, 44, 30).utc_offset, 86400), 0)
-    end
-    with_env_tz 'NZ' do
-      assert_equal Time.local(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, Rational(Time.local(2005, 2, 21, 17, 44, 30).utc_offset, 86400), 0)
-    end
-    assert_equal ::Date::ITALY, Time.utc(2005, 2, 21, 17, 44, 30).to_datetime.start # use Ruby's default start value
+  def test_conversion_methods_are_publicized
+    assert Time.public_instance_methods.include?(:to_date)     || Time.public_instance_methods.include?('to_date')
+    assert Time.public_instance_methods.include?(:to_datetime) || Time.public_instance_methods.include?('to_datetime')
   end
 
   def test_to_time