title: Rails: Find entries by date
body: <p>I'm running Ruby 2 and Rails 4.</p>
  
  <p>I am creating an app where you can track the calories and macronutrients of each meal entered on a particular day, but I would like the ability to look back at previous days.</p>
  
  <p>I have a table showing what meals have been entered today on my index page through a scope in my model. How would I implement the ability to look back at other days in Rails? </p>
  
  <p>Should I add in a date model or give each meal a datetime? Is there a gem for this sort of thing?</p>
  
  <p><strong>Meals Model</strong></p>
  
  <pre><code>class Meal &lt; ActiveRecord::Base
  
    scope :today, lambda { 
      where("created_at &gt; ?", Time.now.beginning_of_day)
      .where("created_at &lt; ?", Time.now.end_of_day) 
    }
  
    scope :previous, lambda {
      where("created_at &lt; ?", Time.now.beginning_of_day) 
    }
  
    validates :name, presence: true
    validates :calories, presence: true, numericality: { only
    validates :protein, numericality: { only_integer: true }
    validates :carbohydrates, numericality: { only_integer: t
    validates :fats, numericality: { only_integer: true }
  
    belongs_to :user
  
  end
  </code></pre>
  
  <p><strong>Meals Controller</strong></p>
  
  <pre><code>  def index
      if user_signed_in?
        @todays_meals = current_user.meals.today
        unless current_user.bmr.blank? || current_user.weight.blank? || current_user.protein_intake.blank? || current_user.fat_percentage.blank?
          @remaining_calories = (current_user.bmr) - @todays_meals.sum(:calories)
          @remaining_protein = current_user.protein_intake - @todays_meals.sum(:protein)
          @remaining_fats = (current_user.bmr * current_user.fat_percentage / 900).to_i - @todays_meals.sum(:fats)
          @remaining_carbs = carbs_calculator
          @fat_grams = current_user.fat_percentage * current_user.bmr / 900
          @carb_grams = (carbs_calculator + @todays_meals.sum(:carbohydrates))
        end
      else
        @no_header = true
      end
    end
  </code></pre>
  
  <p>Thanks!</p>