Rails cache expire

I have a rails application, in that I am using simple rails cache. My testing is as follows:

Rails.cache.write('temp',Date.today,:expires_in => 60.seconds)

I can read it through Rails.cache.read('temp') and Rails.cache.fetch('temp').

The problem is it doesn't expire. It will still be alive after 60 seconds. Can any one tell me what is missing here.

FYI: I have declared in my development.rb as follows :

config.action_controller.perform_caching = true

config.cache_store = :memory_store

Is there anything I missed out? I want to expires my cache.