diff --git a/lib/validates_timeliness/validator.rb b/lib/validates_timeliness/validator.rb
index 7d05fd3..55ebe5f 100644
--- a/lib/validates_timeliness/validator.rb
+++ b/lib/validates_timeliness/validator.rb
@@ -18,7 +18,7 @@ module ValidatesTimeliness
 
     def initialize(options)
       @allow_nil, @allow_blank = options.delete(:allow_nil), options.delete(:allow_blank)
-      @type = options.delete(:type)
+      @type = options.delete(:type) || :datetime
       @check_restrictions = RESTRICTIONS.keys & options.keys
 
       if range = options.delete(:between)
diff --git a/spec/validates_timeliness/validator_spec.rb b/spec/validates_timeliness/validator_spec.rb
index ad2ccc8..26d5fef 100644
--- a/spec/validates_timeliness/validator_spec.rb
+++ b/spec/validates_timeliness/validator_spec.rb
@@ -19,6 +19,11 @@ describe ValidatesTimeliness::Validator do
       invalid!(:birth_date, Date.new(2010,1,2))
       valid!(:birth_date, Date.new(2010,1,1))
     end
+
+    it 'should use default to :datetime type' do
+      Person.validates :birth_datetime, :timeliness => {:is_at => Time.mktime(2010,1,1)}
+      Person.validators.first.instance_variable_get(:@type).should == :datetime
+    end
   end
 
   describe ":allow_nil option" do