How would you store a business's hours in the db/model of a Rails app?

I'm creating a Rails app that will store the opening and closing hours for a business. Originally, I thought of simply using a text data type and letting it be free-form:

"Monday to Friday 9am to 5pm
Saturday 11am to 4pm
Closed Sundays"

But, requirements have changed and I need to check the hours against the current date & time and display an "Open" or "Closed" in the view. Something like:

class Business < ActiveRecord::Base

  def open?
    # Something like ... 
    Time.now > open_time && Time.now < close_time
  end

end

So what would be the best way to tackle this in terms of storing the hours for each day of the week? Should the Business simply has_many :open_blocks (or whatever) that have open and close times? Should I just store the day as a string?