def parse(date)
			return date if date.kind_of?(self)
			r=[]
			dates = date.to_s.chomp.split(/,\s*/)
			dates.each do |d|
				r << d.split(/\s*->\s*/).map {|i| i == ":now" ? :now : i }
			end
			return DateRange.new(r)
		end
def parse(date)
			return date if date.kind_of?(self)
			r=[]
			dates = date.to_s.chomp.split(/,\s*/)
			dates.each do |d|
				r << d.split(/\s*->\s*/).map {|i| i == ":now" ? :now : i }
			end
			return DateRange.new(r)
		end
in: 2014-01-02 -> 2014-01-03, 2014-01-05, 2014-02 -> :now
out: [[2014-01-02,2014-01-03],[2014-01-05],[2014-02,:now]]