Business Hours is a Ruby script which will determine the guaranteed time given a business hour schedule.  Implements Business Hours, update, closed, closed?, and each iterator for Business Hours.  As defined in the RPCFN: Business Hours (#10) challenge:

http://rubylearning.com/blog/2010/05/25/rpcfn-business-hours-10/

Updated from feedback and verified that Day Light Saving time is handled correctly.

Create Business Hour object
	hours = BusinessHours.new("9:00 AM", "3:00 PM")

Updating Hours:
  Week Days are updated using Symbol and start/close hours as strings.
	hours.update :fri, "10:00 AM", "5:00 PM"
	hours.update :sat, "9:00 AM", "9:30 PM"

  Specific Days are updated using a Time or String Object and start/close hours as strings.
	hours.update "Dec 24, 2010", "8:00 AM", "1:00 PM"
	hours.update(Time.parse("6/11/2010"), "9:00", "10:00")

Closed Hours:
  Method specifying days closed, where symbols (week days) and Time or String Objects define specific days. 
	hours.closed :sun, :wed, "Dec 25, 2010"