User and hour model

hour.rb

class Hour < ActiveRecord::Base
  belongs_to :user
  
  validates_with PunchcardValidator #defined in config/initializers/punchclock_validator.rb
  validates_presence_of :role, :message => "can't be blank"
  validates_associated :user
  validates_numericality_of :manual, :allow_nil => true
  validates_presence_of :start_time, :if => :punchcard?
  validates_presence_of :manual, :if => :manual?
  
  scope :punched_in, where{start_time.not_eq nil}.where{end_time.eq nil}
  
  def punchcard?
    !start_time.blank? && manual.blank?
  end
  
  def manual?
    !manual.blank? && start_time.blank?
  end
  
  def self.punch_in
    create!(:start_time => Time.now)
  end
  
  def punch_out
    update_attribute(:end_time, Time.now)
  end
  
end

user.rb

class User < ActiveRecord::Base
  validates_presence_of :name
  validates_uniqueness_of :name, :email, :case_sensitive => false
  # Include default devise modules. Others available are:
  # :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :recoverable, :registerable,
         :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :name, :role, :email, :password, :password_confirmation, :remember_me
  
  has_many :hours
  delegate :punched_in, :punch_in, :to => :hours
  
  def punchcard
    punched_in.first
  end
  
  def punch_out
    punchcard.punch_out
  end
  
  def punched_in?
    !punchcard.blank?
  end
end