#in my User.rb file

require "digest/sha1"
@@current_user = nil
class User < ActiveRecord::Base

  def self.authenticate(email, password)
    user = User.find_by_email_address(
                     email,
                     :conditions => ["email_address = ? AND hashed_password = ?",
                     email, Digest::SHA1.hexdigest(password)],
                     :limit => 1)
    if user.blank?
      return false
    end
    self.set_current_user(user.id)
  end

  def self.get_current_user
    @@current_user
  end

  def self.set_current_user(user)
    @@current_user = user
  end


end

#in my TimeTag.rb file

  def self.count_tags_on_day(day = Date.today, user = User.get_current_user)
    self.count( :all, :conditions => ["created_at LIKE ? AND user_id = ?", day.to_s(:db) + '%', user] )
  end

  def self.sum_tags_on_day(day = Date.today, user = User.get_current_user)
    TimeTag.sum( :time, :conditions => ["created_at LIKE ? AND user_id = ?", day.to_s(:db) + "%", user] )
  end