In answer to the question (thanks for posting your question!), Day 0 is when the progesterone goes over 0.9 -- for Cadi that was Friday.
So Friday was Day 0, Saturday Day 1, Sunday Day 2 (probable ovulation day).
The eggs take some time to "ripen" and so cannot be fertilized for an addition 1 - 2 days. So the soonest that fertilization can begin is on Day 3, which is Monday but more likely is that everything is in the right place on Day 4, which is Tuesday. By Day 5 things are starting to wind down, although available eggs remain -- this is all according to the Concannon article, by the way.
And so I want Cadi bred on Day 4 (Tuesday) for sure, and also on Wednesday. If she is bred on those two days, we should have a pregnant girl.
Last night I received the contract from the stud dog owner, and I just need to verify that she will remove the wording that gives her the option of a puppy instead of a stud fee. Although I understand why a stud dog owner would want the option of a puppy, that just doesn't work for me and so such language is a Dealbreaker -- but I am hopeful that it was left in by mistake as we had already discussed this and she agreed to just take a stud fee.
So still ironing out details -- yikes! But Dear Husband and Cadi will leave tomorrow morning and find a Puppy Daddy someplace ;)