Rails and Redis: how should I handle validation here?
In your model.

You can include ActiveModel::Validations directly in your model without relying on ActiveRecord for persistence.

See ActiveModel::Validations &amp; the date_validator gem

A quick example more relevant to you;

class MyThingie

  include ActiveModel::Validations

  validates :start_date, :presence =&gt; true 
  validates :end_date,   :presence =&gt; true 

  # Check out the date_validator gem, it allows things like 
  validates_date_of :end_date, :after =&gt; :start_date

  validates_format_of :location, :with =&gt; /[A-Za-z]/

  # ... 
end