date_scopes.rb

module DateScopes
  extend ActiveSupport::Concern

  module ClassMethods

    def define_date_scopes(*scope_columns)
      scope_columns.map(&:to_s).each do |column|
        match_data = column.match(/^(.*)_at$/)
        name = match_data ? match_data[1] : column

        from_date = "#{name}_from".to_sym
        scope from_date, -> (date) do
          where("#{self.table_name}.#{column} >= ?", scope_value(column, date, :beginning_of_day))
        end

        to_date = "#{name}_to".to_sym
        scope to_date, -> (date) do
          where("#{self.table_name}.#{column} <= ?", scope_value(column, date, :end_of_day))
        end

        between_dates = "#{name}_between".to_sym
        scope between_dates, -> (from, to) do
          self.send(from_date, from).send(to_date, to)
        end
      end
    end

    private

    def scope_value(column, value, time = nil)
      case date_column_types[column]
      when :date     then value.to_date
      when :datetime then value.to_datetime.in_time_zone.send(time)
      end
    end

    def date_column_types
      @date_column_types ||= self.columns_hash.each_with_object({}) do |(name, column), hash|
        hash[name] = column.type if [:date, :datetime].include?(column.type)
      end
    end

  end
end
ActiveRecord::Base.send(:include, DateScopes)

Let your Post model has created_at and published_at fields.
You can specify in models/post.rb
define_date_scopes :created_at, :published_at

Now Post model has scopes

• created_from, created_to, created_between
• published_from, published_to, published_between