May be of use if you are tracking a certain Track Machine. Every Weekday/Weekend Track Machine Timings are posted for each company along with a headcode.
Timings...http://www.wwwagons.com/timings-f280.html (requests for full timings are always answered)
Headcodes are unique for each track machine... List Here...http://www.wwwagons.com/track-machine-s-headcodes-t60995.html
Please Feel Free to Take a Look :)