ERB not working

gistfile1.rb

require 'erb'

weekday = Time.now.strftime('%A')
simple_template = "Today is <%= weekday %>."

renderer = ERB.new(simple_template)
puts output = renderer.result()

# This throws:
# NameError: undefined local variable or method `weekday' for #<Object:0x10116b2a8>
#	from (erb):1

### Solution:
puts output = renderer.result(binding)
# this magically binds globals and pass them to the template.