3 files changed, 11 insertions, 3 deletions
diff --git a/activemodel/lib/active_model/attribute_assignment.rb b/activemodel/lib/active_model/attribute_assignment.rb
index 087d11f708..62014cd1cd 100644
--- a/activemodel/lib/active_model/attribute_assignment.rb
+++ b/activemodel/lib/active_model/attribute_assignment.rb
@@ -27,7 +27,7 @@ module ActiveModel
       if !new_attributes.respond_to?(:stringify_keys)
         raise ArgumentError, "When assigning attributes, you must pass a hash as an argument."
       end
-      return if new_attributes.blank?
+      return if new_attributes.nil? || new_attributes.empty?
 
       attributes = new_attributes.stringify_keys
       _assign_attributes(sanitize_for_mass_assignment(attributes))
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index 0ab8df42f5..6e2e5afd1b 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -26,6 +26,10 @@ module ActiveModel
   #
   #     define_attribute_methods :name
   #
+  #     def initialize(name)
+  #       @name = name
+  #     end
+  #
   #     def name
   #       @name
   #     end
@@ -54,7 +58,7 @@ module ActiveModel
   #
   # A newly instantiated +Person+ object is unchanged:
   #
-  #   person = Person.new
+  #   person = Person.new("Uncle Bob")
   #   person.changed? # => false
   #
   # Change the name:
diff --git a/activemodel/lib/active_model/type/time.rb b/activemodel/lib/active_model/type/time.rb
index 7101bad566..fe09f63a87 100644
--- a/activemodel/lib/active_model/type/time.rb
+++ b/activemodel/lib/active_model/type/time.rb
@@ -29,7 +29,11 @@ module ActiveModel
         return value unless value.is_a?(::String)
         return if value.empty?
 
-        dummy_time_value = "2000-01-01 #{value}"
+        if value =~ /^2000-01-01/
+          dummy_time_value = value
+        else
+          dummy_time_value = "2000-01-01 #{value}"
+        end
 
         fast_string_to_time(dummy_time_value) || begin
           time_hash = ::Date._parse(dummy_time_value)