Iterate over days, starting from x date through an end date

You can use ranges :

(Date.new(2012, 01, 01)..Date.new(2012, 01, 30)).each do |date|
  # Do stuff with date
end

or (see @awendt answer)

Date.new(2012, 01, 01).upto(Date.new(2012, 01, 30)) do |date|
  # Do stuff with date
end