List the short description of my git commits since a given date, grouped by day.

output sample

> whathaveidone 2013-02-18                                                                                                                                                

Tuesday, 19 February, 2013
      Fix the rake task to pull the real data!
      Correct off-by-one error

Wednesday, 20 February, 2013
      Wrap deep properties with presenters

Thursday, 21 February, 2013
      Code style
      Remove troubleshooting code
      Have presenters wrap deep attributes
      clean-up
      Renamve view variable
      Change to lazy-loading for all sub-attributes
      Install model-view binding libraries
      Move image_url transformation into presenters
      Pass product details to client js object
      Make presenters serializable as json
      Add notes for things to check later
      Present consistent data structure for product prices
      Present consistent data structure for product images
      Present all image url attributes anywhere as working urls

Friday, 22 February, 2013
      Present all products with array of 1 or more 'variants'
      Utilize color images as simple proof of concept
      whitespace
      Move embedded javascript out of product show view
      Add variant 'dump' view for internal use

Saturday, 23 February, 2013
      Convert rivets.js config to CoffeeScript
      Configure rivets.js to read nested model properties
      Allow shopper to select product variant
      Keep product/show js from running on other pages
      Don't show variants choice if only 1 variant
      Simply data-binding code by making adaptor smarter
      Shorten code with CoffeeScript awesomeness
      Comment rivets adaptor for clarity

whathaveidone

#!/usr/bin/env ruby

require 'chronic'
since = ARGV[0] ? Chronic.parse(ARGV[0]).to_date : Date.today

(since..Date.today).each do |d|
  if (lines = `git shortlog --author="$GIT_AUTHOR_NAME" --since=#{d - 1} --until=#{d}`.split("\n")[1..-1])
    puts d.strftime('%A, %d %B, %Y'),
         lines.compact,
         ''
  end
end