# File lib/ice_cube/schedule.rb, line 18
    def initialize(start_time = nil, options = {})
      self.start_time = start_time || TimeUtil.now
      self.end_time = self.start_time + options[:duration] if options[:duration]
      self.end_time = options[:end_time] if options[:end_time]
      @all_recurrence_rules = []
      @all_exception_rules = []
      yield self if block_given?
    end