There will be a morning walk thru and an afternoon walk thru. Usually the morning begins with a gathering of everyone for announcements, clarifications, National Anthems, etc. And that usually starts around 7. After that is over then there is the morning walk thru. You walk in groups according to what division you are in - Standard, Double Digit, Vet, etc. And that morning walk thru takes awhile to get everyone done. Though this year since there are 2 rings it will be faster.
After all morning rounds are run there will be a break in the action and a rebuilding of the afternoon course(s). Then there will be a walk thru just like in the morning - by groups. Not really any way to specify a time. Especially since there are 2 rings this year - so "historical data" won't be as helpful.
And where you are in the walk thru groups lines up with where your group is in the run order. So that changes each day as well.