Ruby/Time/timer

#!/usr/bin/env ruby
def timer( start )
    puts "Minutes: " + start.to_s
    start_time = Time.now
    puts start_time.strftime("Start to_time: %I:%M:%S %p")
    start.downto(1) { |i| sleep 60 }
    end_time = Time.now
    print end_time.strftime("Elapsed time: %I:%M:%S %p")
end
timer 1