fix problem with handling time of 00:00

README

@@ -11,3 +11,6 @@ USAGE:
 
 Authors: Nick Muerdter (original code)
          Maurice Aubrey <maurice.aubrey+12hour@gmail.com>
+
+Home Page:
+http://code.google.com/p/rails-twelve-hour-time-plugin/

lib/12_hour_time.rb

@@ -24,20 +24,16 @@ module ActionView::Helpers::DateHelper
   def select_hour_with_ampm(datetime, options = {}) 
     options[:twelve_hour] or return select_hour_without_ampm(datetime, options)
 
-    val = ''
-    if datetime
-      val = datetime.kind_of?(Fixnum) ? datetime : datetime.hour
-      val -= 12 if val > 12
-    end
+    hour = _12_hour(datetime)
 
     if options[:use_hidden]
-      return hidden_html(options[:field_name] || 'hour', val, options)
+      return hidden_html(options[:field_name] || 'hour', hour, options)
     end
 
     hour_options = []
-    1.upto(12) do |hour|
+    1.upto(12) do |val|
       selected = (hour == val) ? ' selected="selected"' : ''
-      hour_options << %(<option value="#{leading_zero_on_single_digits(hour)}"#{selected}>#{leading_zero_on_single_digits(hour)}</option>\n)
+      hour_options << %(<option value="#{leading_zero_on_single_digits(val)}"#{selected}>#{leading_zero_on_single_digits(val)}</option>\n)
     end
 
     select_html(options[:field_name] || 'hour', hour_options, options)
@@ -73,6 +69,17 @@ def select_time_with_ampm(datetime = Time.now, options = {})
   end
 
   alias_method_chain :select_time, :ampm
+
+  private
+
+    def _12_hour(datetime)
+      return '' if datetime.blank?
+
+      hour = datetime.kind_of?(Fixnum) ? datetime : datetime.hour
+      hour -= 12 if hour > 12
+
+      return hour
+    end
 end
 
 class ActionView::Helpers::InstanceTag

test/12_hour_time_test.rb

@@ -19,6 +19,14 @@ class TwelveHourTimeTest < Test::Unit::TestCase
   include ActionView::Helpers::FormOptionsHelper
   include ActionView::Helpers::DateHelper
 
+  def test_24_to_12_hour
+    assert_equal(12, _12_hour(0), "12 AM")
+    assert_equal(1, _12_hour(1), "1 AM")
+    assert_equal(12, _12_hour(12), "12 PM")
+    assert_equal(1, _12_hour(13), "1 PM")
+    assert_equal(12, _12_hour(24), "12 AM")
+  end
+
   def test_select_hour_12
     time = Time.parse '2005-07-27 15:03:34'