There are a few ways to solve this problem. However, I think the easiest is to cache the day of the year that the user is born on as an integer. If stored alongside the timestamp we can quickly get a list but properly handle the full birthday elsewhere, s...

You can easily chain scopes together in your models. class Article < ActiveRecord::Base scope :ordered, order('position ASC') scope :published, ordered.where('published = ?', true) scope :for_homepage, published.limit(3) end Article.for_homepage...

The module and class below demonstrate how to use instance methods and class methods from "module mixins". The thing to remember is scope. For instance, to use class methods within instance methods you need to call them from the class itself. This is acco...