diff --git a/actionpack/lib/action_view/helpers/date_helper.rb b/actionpack/lib/action_view/helpers/date_helper.rb
index ee9f0da9b8..be67042999 100644
--- a/actionpack/lib/action_view/helpers/date_helper.rb
+++ b/actionpack/lib/action_view/helpers/date_helper.rb
@@ -674,9 +674,9 @@ module ActionView
         @options[:discard_minute] ||= true if @options[:discard_hour]
         @options[:discard_second] ||= true unless @options[:include_seconds] && !@options[:discard_minute]
 
-        # If the day is hidden and the month is visible, the day should be set to the 1st so all month choices are
-        # valid (otherwise it could be 31 and February wouldn't be a valid date)
-        if @datetime && @options[:discard_day] && !@options[:discard_month]
+        # If the day is hidden, the day should be set to the 1st so all month and year choices are valid. Otherwise,
+        # February 31st or February 29th, 2011 can be selected, which are invalid.
+        if @datetime && @options[:discard_day]
           @datetime = @datetime.change(:day => 1)
         end
 
@@ -701,9 +701,9 @@ module ActionView
         @options[:discard_month]  ||= true unless order.include?(:month)
         @options[:discard_day]    ||= true if @options[:discard_month] || !order.include?(:day)
 
-        # If the day is hidden and the month is visible, the day should be set to the 1st so all month choices are
-        # valid (otherwise it could be 31 and February wouldn't be a valid date)
-        if @datetime && @options[:discard_day] && !@options[:discard_month]
+        # If the day is hidden, the day should be set to the 1st so all month and year choices are valid. Otherwise,
+        # February 31st or February 29th, 2011 can be selected, which are invalid.
+        if @datetime && @options[:discard_day]
           @datetime = @datetime.change(:day => 1)
         end
 
diff --git a/actionpack/test/template/active_model_helper_test.rb b/actionpack/test/template/active_model_helper_test.rb
index 18468ee91a..24511df444 100644
--- a/actionpack/test/template/active_model_helper_test.rb
+++ b/actionpack/test/template/active_model_helper_test.rb
@@ -43,14 +43,14 @@ class ActiveModelHelperTest < ActionView::TestCase
 
   def test_date_select_with_errors
     assert_dom_equal(
-      %(<div class="field_with_errors"><select id="post_updated_at_1i" name="post[updated_at(1i)]">\n<option selected="selected" value="2004">2004</option>\n<option value="2005">2005</option>\n</select>\n<input id="post_updated_at_2i" name="post[updated_at(2i)]" type="hidden" value="6" />\n<input id="post_updated_at_3i" name="post[updated_at(3i)]" type="hidden" value="15" />\n</div>),
+      %(<div class="field_with_errors"><select id="post_updated_at_1i" name="post[updated_at(1i)]">\n<option selected="selected" value="2004">2004</option>\n<option value="2005">2005</option>\n</select>\n<input id="post_updated_at_2i" name="post[updated_at(2i)]" type="hidden" value="6" />\n<input id="post_updated_at_3i" name="post[updated_at(3i)]" type="hidden" value="1" />\n</div>),
       date_select("post", "updated_at", :discard_month => true, :discard_day => true, :start_year => 2004, :end_year => 2005)
     )
   end
 
   def test_datetime_select_with_errors
     assert_dom_equal(
-      %(<div class="field_with_errors"><input id="post_updated_at_1i" name="post[updated_at(1i)]" type="hidden" value="2004" />\n<input id="post_updated_at_2i" name="post[updated_at(2i)]" type="hidden" value="6" />\n<input id="post_updated_at_3i" name="post[updated_at(3i)]" type="hidden" value="15" />\n<select id="post_updated_at_4i" name="post[updated_at(4i)]">\n<option selected="selected" value="00">00</option>\n<option value="01">01</option>\n<option value="02">02</option>\n<option value="03">03</option>\n<option value="04">04</option>\n<option value="05">05</option>\n<option value="06">06</option>\n<option value="07">07</option>\n<option value="08">08</option>\n<option value="09">09</option>\n<option value="10">10</option>\n<option value="11">11</option>\n<option value="12">12</option>\n<option value="13">13</option>\n<option value="14">14</option>\n<option value="15">15</option>\n<option value="16">16</option>\n<option value="17">17</option>\n<option value="18">18</option>\n<option value="19">19</option>\n<option value="20">20</option>\n<option value="21">21</option>\n<option value="22">22</option>\n<option value="23">23</option>\n</select>\n : <select id="post_updated_at_5i" name="post[updated_at(5i)]">\n<option selected="selected" value="00">00</option>\n</select>\n</div>),
+      %(<div class="field_with_errors"><input id="post_updated_at_1i" name="post[updated_at(1i)]" type="hidden" value="2004" />\n<input id="post_updated_at_2i" name="post[updated_at(2i)]" type="hidden" value="6" />\n<input id="post_updated_at_3i" name="post[updated_at(3i)]" type="hidden" value="1" />\n<select id="post_updated_at_4i" name="post[updated_at(4i)]">\n<option selected="selected" value="00">00</option>\n<option value="01">01</option>\n<option value="02">02</option>\n<option value="03">03</option>\n<option value="04">04</option>\n<option value="05">05</option>\n<option value="06">06</option>\n<option value="07">07</option>\n<option value="08">08</option>\n<option value="09">09</option>\n<option value="10">10</option>\n<option value="11">11</option>\n<option value="12">12</option>\n<option value="13">13</option>\n<option value="14">14</option>\n<option value="15">15</option>\n<option value="16">16</option>\n<option value="17">17</option>\n<option value="18">18</option>\n<option value="19">19</option>\n<option value="20">20</option>\n<option value="21">21</option>\n<option value="22">22</option>\n<option value="23">23</option>\n</select>\n : <select id="post_updated_at_5i" name="post[updated_at(5i)]">\n<option selected="selected" value="00">00</option>\n</select>\n</div>),
       datetime_select("post", "updated_at", :discard_year => true, :discard_month => true, :discard_day => true, :minute_step => 60)
     )
   end
diff --git a/actionpack/test/template/date_helper_test.rb b/actionpack/test/template/date_helper_test.rb
index 1d934b153f..f622097b57 100644
--- a/actionpack/test/template/date_helper_test.rb
+++ b/actionpack/test/template/date_helper_test.rb
@@ -711,7 +711,7 @@ class DateHelperTest < ActionView::TestCase
     # Since the order is incomplete nothing will be shown
     expected = %(<input id="date_first_year" name="date[first][year]" type="hidden" value="2003" />\n)
     expected << %(<input id="date_first_month" name="date[first][month]" type="hidden" value="8" />\n)
-    expected << %(<input id="date_first_day" name="date[first][day]" type="hidden" value="16" />\n)
+    expected << %(<input id="date_first_day" name="date[first][day]" type="hidden" value="1" />\n)
 
     assert_dom_equal expected, select_date(Time.mktime(2003, 8, 16), :start_year => 2003, :end_year => 2005, :prefix => "date[first]", :order => [:day])
   end
@@ -943,7 +943,7 @@ class DateHelperTest < ActionView::TestCase
     expected << "</select>\n"
 
     expected << %(<input type="hidden" id="date_first_month" name="date[first][month]" value="8" />\n)
-    expected << %(<input type="hidden" id="date_first_day" name="date[first][day]" value="16" />\n)
+    expected << %(<input type="hidden" id="date_first_day" name="date[first][day]" value="1" />\n)
 
     assert_dom_equal expected, select_date(Time.mktime(2003, 8, 16), { :date_separator => " / ", :discard_month => true, :discard_day => true, :start_year => 2003, :end_year => 2005, :prefix => "date[first]"})
   end
@@ -1396,6 +1396,20 @@ class DateHelperTest < ActionView::TestCase
     assert_dom_equal expected, date_select("post", "written_on", :order => [ :month, :year ])
   end
 
+  def test_date_select_without_day_and_month
+    @post = Post.new
+    @post.written_on = Date.new(2004, 2, 29)
+
+    expected = "<input type=\"hidden\" id=\"post_written_on_2i\" name=\"post[written_on(2i)]\" value=\"2\" />\n"
+    expected << "<input type=\"hidden\" id=\"post_written_on_3i\" name=\"post[written_on(3i)]\" value=\"1\" />\n"
+
+    expected << %{<select id="post_written_on_1i" name="post[written_on(1i)]">\n}
+    expected << %{<option value="1999">1999</option>\n<option value="2000">2000</option>\n<option value="2001">2001</option>\n<option value="2002">2002</option>\n<option value="2003">2003</option>\n<option value="2004" selected="selected">2004</option>\n<option value="2005">2005</option>\n<option value="2006">2006</option>\n<option value="2007">2007</option>\n<option value="2008">2008</option>\n<option value="2009">2009</option>\n}
+    expected << "</select>\n"
+
+    assert_dom_equal expected, date_select("post", "written_on", :order => [ :year ])
+  end
+
   def test_date_select_without_day_with_separator
     @post = Post.new
     @post.written_on = Date.new(2004, 6, 15)
@@ -2427,7 +2441,7 @@ class DateHelperTest < ActionView::TestCase
     1999.upto(2009) { |i| expected << %(<option value="#{i}"#{' selected="selected"' if i == 2004}>#{i}</option>\n) }
     expected << "</select>\n"
     expected << %{<input type="hidden" id="post_updated_at_2i" name="post[updated_at(2i)]" value="6" />\n}
-    expected << %{<input type="hidden" id="post_updated_at_3i" name="post[updated_at(3i)]" value="15" />\n}
+    expected << %{<input type="hidden" id="post_updated_at_3i" name="post[updated_at(3i)]" value="1" />\n}
 
     expected << " &mdash; "
 
@@ -2448,7 +2462,7 @@ class DateHelperTest < ActionView::TestCase
 
     expected = %{<input type="hidden" id="post_updated_at_1i" name="post[updated_at(1i)]" value="2004" />\n}
     expected << %{<input type="hidden" id="post_updated_at_2i" name="post[updated_at(2i)]" value="6" />\n}
-    expected << %{<input type="hidden" id="post_updated_at_3i" name="post[updated_at(3i)]" value="15" />\n}
+    expected << %{<input type="hidden" id="post_updated_at_3i" name="post[updated_at(3i)]" value="1" />\n}
 
     expected << %{<select id="post_updated_at_4i" name="post[updated_at(4i)]">\n}
     0.upto(23) { |i| expected << %(<option value="#{sprintf("%02d", i)}"#{' selected="selected"' if i == 15}>#{sprintf("%02d", i)}</option>\n) }
@@ -2467,7 +2481,7 @@ class DateHelperTest < ActionView::TestCase
 
     expected = %{<input type="hidden" id="post_updated_at_1i" disabled="disabled" name="post[updated_at(1i)]" value="2004" />\n}
     expected << %{<input type="hidden" id="post_updated_at_2i" disabled="disabled" name="post[updated_at(2i)]" value="6" />\n}
-    expected << %{<input type="hidden" id="post_updated_at_3i" disabled="disabled" name="post[updated_at(3i)]" value="15" />\n}
+    expected << %{<input type="hidden" id="post_updated_at_3i" disabled="disabled" name="post[updated_at(3i)]" value="1" />\n}
 
     expected << %{<select id="post_updated_at_4i" disabled="disabled" name="post[updated_at(4i)]">\n}
     0.upto(23) { |i| expected << %(<option value="#{sprintf("%02d", i)}"#{' selected="selected"' if i == 15}>#{sprintf("%02d", i)}</option>\n) }