Time.zone.parse: return nil for strings with no date information

activerecord/lib/active_record/attribute_methods.rb

@@ -179,7 +179,7 @@ def define_write_method(attr_name)
         def define_write_method_for_time_zone_conversion(attr_name)
           method_body = <<-EOV
             def #{attr_name}=(time)
-              unless time.blank? || time.acts_like?(:time)
+              unless time.acts_like?(:time)
                 time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
               end
               time = time.in_time_zone rescue nil if time

activesupport/lib/active_support/values/time_zone.rb

@@ -213,8 +213,10 @@ def at(secs)
   #   Time.zone.now                 # => Fri, 31 Dec 1999 14:00:00 HST -10:00
   #   Time.zone.parse('22:30:00')   # => Fri, 31 Dec 1999 22:30:00 HST -10:00
   def parse(str, now=now)
+    date_parts = Date._parse(str)
+    return if date_parts.blank?
     time = Time.parse(str, now) rescue DateTime.parse(str)
-    if Date._parse(str)[:offset].nil?
+    if date_parts[:offset].nil?
       ActiveSupport::TimeWithZone.new(nil, self, time)
     else
       time.in_time_zone(self)

activesupport/test/time_zone_test.rb

@@ -198,6 +198,14 @@ def test_parse_far_future_date_with_time_zone_offset_in_string
       assert_equal zone, twz.time_zone
     end
   end
+  
+  def test_parse_returns_nil_when_string_without_date_information_is_passed_in
+    silence_warnings do # silence warnings raised by tzinfo gem
+      zone = TimeZone['Eastern Time (US & Canada)']
+      assert_nil zone.parse('foobar')
+      assert_nil zone.parse('   ')
+    end
+  end
 
   uses_mocha 'TestParseWithIncompleteDate' do
     def test_parse_with_incomplete_date