threw together some code to parse heroku downtime json to determine relevance to app

parse.rb

require 'rubygems'
require 'json'
require 'date'

ignore = ["Shared Database Server Offline", "Elevated Error Rates Around Bamboo", "Emergency Maintenance Window on Bamboo and Aspen HTTP stacks", "Emergency Maintenance Window for Aspen/Bamboo Deploys", "Intermittent Git Errors", "Emergency Maintenance on a Shared Database Server", "Emergency Maintenance on Logging Infrastructure ", "Errors Launching Terminal Attached Processes"]

records = ""
File.open("issues.json") do |file|
  file.readlines.each do |line|
    records += line
  end
end

json = JSON.parse(records)
relevent = json.select {|incident| DateTime.parse(incident["created_at"]) <= DateTime.new(2012,4,1) && [incident["title"]] & ignore == []}

total_downtime = 0
relevent.each do |incident|
  updates = incident["updates"].select { |update| update["update_type"] == "resolved"}
  last_update = updates.first #there can be more than one 'resolved' update but the only example i've seen had the same timestamp for both records

  duration = DateTime.parse(last_update["created_at"]) - DateTime.parse(incident["created_at"])

  total_downtime += duration
end

puts "hours: #{(total_downtime * 24).to_f}"
puts "minutes: #{(total_downtime * 24 * 60).to_f}"
puts "seconds: #{(total_downtime * 24 * 60 * 60).to_i}"
puts "incidents: #{relevent.count}"

puts "descriptions:"
relevent.each { |incident| puts incident["title"]}