Ruby script to adjust timestamps in Garmin Training Center XML files (TCX)

tcx_adjust_time.rb

#!/usr/bin/env ruby
require 'time'
require 'rexml/document'

DELTA = -(24 * 3600 * 7 - 7 * 3600)
raw = IO.read(ARGV[0])
doc = REXML::Document.new(raw)

id_written = false
doc.elements.each('//Activity/Lap') do |lap|
  lap.elements.each('Track/Trackpoint') do |ele|
    t = Time.parse(ele.elements['Time'].text) + DELTA
    ele.elements['Time'].text = t.iso8601
  end
  lapStart = (Time.parse(lap.attributes['StartTime']) + DELTA).iso8601
  lap.attributes['StartTime'] = lapStart

  if not id_written  then
    doc.elements['//Activity/Id'].text = lapStart
    id_written = true
  end
end

puts doc.to_s

Yesterday's run was about a week off (It's a GPS watch, goddammit!), the only way for me to fix this recording was to export it, adjust the timestamps using tcx_adjust_time BLA.tcx > NEW_BLA.tcx and re-import into Garmin Training Center.

https://twitter.com/megametre/status/530277305160335360