Question: I've just started working Elixir & Phoenix today, i am trying to add Ecto as a mapper, but i'm having some trouble using time.

This is my model.

```elixir
  schema "users" do
    field :name, :string
    field :email, :string
    field :created_at, :datetime, default: Ecto.DateTime.local
    field :updated_at, :datetime, default: Ecto.DateTime.local
  end

```

I'm trying to set the created\_at and updated\_at per default, but when i try to compile this, i get the following error.

```
== Compilation error on file web/models/user.ex ==
** (ArgumentError) invalid default argument `%Ecto.DateTime{day: 13, hour: 19, min: 47, month: 2, sec: 12, year: 2015}` for `:datetime`
lib/ecto/schema.ex:687: Ecto.Schema.check_default!/2
lib/ecto/schema.ex:522: Ecto.Schema.__field__/4
web/models/board.ex:9: (module)
(stdlib) erl_eval.erl:657: :erl_eval.do_apply/6

```

There is not much help to get in the documentation, what would be the correct way to do this?

Answer: 
Defaults fields names are `:inserted_at` and `:updated_at` but you can merge with your own field names, passing a keyword list

```
schema "users" do
  field :name, :string
  field :email, :string
  timestamps([{:inserted_at,:created_at}])
end

```
You could also consider having the default not be in the schema, but in the migration: `"created_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP"`