elizabrocksoftware.com's Freckle Integration. This drives: http://elizabrocksoftware.com/what_are_they_doing

db schema.rb

# encoding: UTF-8
# This file is auto-generated from the current state of the database. Instead
# of editing this file, please use the migrations feature of Active Record to
# incrementally modify your database, and then regenerate this schema definition.
#
# Note that this schema.rb definition is the authoritative source for your
# database schema. If you need to create the application database on another
# system, you should be using db:schema:load, not running all the migrations
# from scratch. The latter is a flawed and unsustainable approach (the more migrations
# you'll amass, the slower it'll run and the greater likelihood for issues).
#
# It's strongly recommended that you check this file into your version control system.

ActiveRecord::Schema.define(version: 20131113162700) do

  # These are extensions that must be enabled in order to support this database
  enable_extension "plpgsql"

  create_table "active_admin_comments", force: true do |t|
    t.string   "namespace"
    t.text     "body"
    t.string   "resource_id",   null: false
    t.string   "resource_type", null: false
    t.integer  "author_id"
    t.string   "author_type"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  add_index "active_admin_comments", ["author_type", "author_id"], name: "index_active_admin_comments_on_author_type_and_author_id", using: :btree
  add_index "active_admin_comments", ["namespace"], name: "index_active_admin_comments_on_namespace", using: :btree
  add_index "active_admin_comments", ["resource_type", "resource_id"], name: "index_active_admin_comments_on_resource_type_and_resource_id", using: :btree

  create_table "admin_users", force: true do |t|
    t.string   "email",                  default: "", null: false
    t.string   "encrypted_password",     default: "", null: false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",          default: 0
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string   "current_sign_in_ip"
    t.string   "last_sign_in_ip"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  add_index "admin_users", ["email"], name: "index_admin_users_on_email", unique: true, using: :btree
  add_index "admin_users", ["reset_password_token"], name: "index_admin_users_on_reset_password_token", unique: true, using: :btree

  create_table "messages", force: true do |t|
    t.string   "from"
    t.string   "name"
    t.text     "message"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "project_screenshots", force: true do |t|
    t.integer  "project_id"
    t.string   "image"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "project_services", force: true do |t|
    t.integer  "project_id"
    t.integer  "service_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "projects", force: true do |t|
    t.string   "color"
    t.integer  "freckle_id"
    t.string   "logo"
    t.string   "freckle_name"
    t.string   "time_entry_name"
    t.string   "public_project_name"
    t.text     "client_description"
    t.text     "project_goal"
    t.text     "results"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.boolean  "published"
    t.boolean  "testimonial_requested"
  end

  create_table "proposals", force: true do |t|
    t.text     "client_company_overview"
    t.text     "client_needs_overview"
    t.text     "executive_summary"
    t.text     "project_summary"
    t.text     "proposed_schedule"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "service_categories", force: true do |t|
    t.text     "description"
    t.string   "name"
    t.integer  "position"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "services", force: true do |t|
    t.text     "service_description"
    t.integer  "position"
    t.text     "process_description"
    t.integer  "service_category_id"
    t.string   "slug"
    t.string   "name"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "summary"
  end

  create_table "testimonials", force: true do |t|
    t.integer  "project_id"
    t.text     "testimonial"
    t.string   "client_name"
    t.string   "client_company"
    t.string   "client_link"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "time_entries", force: true do |t|
    t.text     "description_text"
    t.date     "entry_date"
    t.integer  "freckle_id"
    t.integer  "freckle_project_id"
    t.integer  "minutes"
    t.text     "tags"
    t.text     "url"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

lib cron.rb

require 'freckle'

class Cron
  def self.run!
    Freckle.import_projects!
    (0..7).each do |i|
      Freckle.import_time_entries!(Time.zone.today - i)
    end
  end
end

lib freckle.rb

require 'httparty'

class Freckle
  include HTTParty
  base_uri 'https://elizabrock.letsfreckle.com/'

  FRECKLE_PROJECT_MAPPINGS = {
    :id => :freckle_id,
    :color_hex => :color,
    :name => :freckle_name
  }

  FRECKLE_TIME_ENTRY_MAPPINGS = {
    :id => :freckle_id,
    :project_id => :freckle_project_id,
    :minutes => :minutes,
    :description_text => :description_text,
    :url => :url,
    :date => :entry_date
  }

  def self.import_projects!
    Freckle.new().import_projects
  end

  def self.import_time_entries! date = nil
    date = Time.zone.today unless date
    raise "Date cannot be in the future" if date.future?
    Freckle.new().import_time_entries(date)
  end

  def import_time_entries date
    options = default_options.merge( 'search[from]' => date.to_s(:freckle), 'search[to]' => date.to_s(:freckle) )
    time_entries = self.class.get('/api/entries.json', :query => options)
    time_entries.collect { |te| import_time_entry(te['entry']) }
  end

  def import_projects
    options = default_options
    projects = self.class.get('/api/projects.json', :query => options)
    projects.collect { |project| import_project(project['project']) }
  end

  private

  def import_time_entry te
    time_entry = TimeEntry.find_or_create_by(freckle_id: te["id"])
    updates = FRECKLE_TIME_ENTRY_MAPPINGS.each_pair do |freckle_attr, time_entry_attr|
      time_entry.send("#{time_entry_attr}=", te[freckle_attr.to_s] || "")
    end
    time_entry.tags = te["tags"].map{|t| t["name"]}.join(", ")
    time_entry.save
    time_entry
  end

  def import_project p
    project = Project.find_or_create_by(freckle_id: p["id"])
    updates = FRECKLE_PROJECT_MAPPINGS.each_pair do |freckle_attr, project_attr|
      project.send("#{project_attr}=", p[freckle_attr.to_s] || "")
    end
    project.save
    project
  end

  def default_options
    {:token => "[my_freckle_api_token]" }
  end
end

lib tasks cron.rb

require 'cron'

desc "Run cron job"
task :cron => :environment do
  Cron.run!
end

spec lib freckle.rb

require 'freckle'
require 'spec_helper'

describe Freckle do
  describe ".import_time_entries!", :vcr do
    context "no arguments" do
      it "calls itself with today's date" do
        Freckle.any_instance.should_receive(:import_time_entries).with(Date.today)
        Freckle.stub(:get).and_return([])
        Freckle.import_time_entries!
      end
    end
    context "with a date argument in the future" do
      it "returns raises an error" do
        expect{ Freckle.import_time_entries!(Date.today + 3) }.to raise_error
      end
      it "does not hit freckle" do
        Freckle.should_not_receive(:import_time_entries)
        expect{ Freckle.import_time_entries!(Date.today + 3) }.to raise_error
      end
    end
    context "with a date argument in the present/past" do
      let(:date){ Date.parse("2011-07-04") }
      let(:existing_project){ Fabricate(:project, freckle_id: 59449) }
      let(:existing_time_entry){ Fabricate(:time_entry, freckle_id: 1103491, freckle_project_id: 59449, minutes: 20, description_text: "Add cucumber compass and rspec.", url: "https://github.com/elizabrock/watchelizago/commit/c426c7872766a68fcbc51809b2f27c89f2eca618", tags: "development", entry_date: Date.parse("2011-07-04")) }
      let(:changed_time_entry){ Fabricate(:time_entry, freckle_id: 1103788, minutes: 345) } #actual time: 10

      before do
        existing_project
        existing_time_entry
        changed_time_entry
      end

      def do_action
        Freckle.import_time_entries!(date)
      end

      it "does not create time entries from other days" do
        do_action.keep_if{|te| te.entry_date != date}.should be_empty
      end

      it "doesn't duplicate existing time entries" do
        do_action
        TimeEntry.where(:freckle_id => existing_time_entry.freckle_id).count.should == 1
      end

      it "returns the new time entries" do
        do_action.map(&:freckle_id).sort.should == [1103459, 1103491, 1103762, 1103779, 1103788, 1103801]
      end

      it "persists all of the time entries" do
        a = do_action
        b = TimeEntry.all
        difference = ( (a || b) - ( a & b) ) #anything that isn't in both sets
        difference.should be_empty
      end

      it "creates time entries that don't exist" do
        TimeEntry.where(freckle_id: 1103762).to_a.should be_empty
        do_action
        TimeEntry.where(freckle_id: 1103762).to_a.should_not be_empty
      end

      it "updates time entries that have changed" do
        expected_attributes = { freckle_id: 1103788, freckle_project_id: 59459, minutes: 10, description_text: "sending anne an email about the upcoming work", url: "", tags: "planning", entry_date: Date.parse("2011-07-04") }
        do_action
        changed_time_entry.reload
        expected_attributes.each_pair do |attr, expected_value|
          changed_time_entry[attr].should == expected_value
        end
      end

      it "doesn't change time entries that haven't changed" do
        expected = existing_time_entry.attributes
        do_action
        actual = TimeEntry.find(existing_time_entry.id)
        actual.attributes.should == expected
      end

      it "creates any projects that don't exist" do
        Project.where(freckle_id: 52665).to_a.should be_empty
        do_action
        Project.where(freckle_id: 52665).to_a.should_not be_empty
      end

      it "doesn't change projects that already exist" do
        expect{ do_action }.to_not change{ existing_project.reload }
      end

      it "doesn't duplicate projects that already exist" do
        do_action
        Project.where(:freckle_id => existing_project.freckle_id).count.should == 1
      end
    end
  end
end

I use the heroku schedule to run rake cron every hour.

The API documentation is here: http://developer.letsfreckle.com/