It's impossible to give a concrete answer because it all depends on a number of variables, such as when the product arrives at the warehouse, and where you live.
Godwin has confirmed on a number of occasions that, whenever possible, they try to ship on Friday so that the game arrives on release day (for a Tuesday release). There is no guarantee that this will happen though, it works on a release by release basis, and there's just no reasonable way to know for sure beforehand.
The general consensus based on previous conversations here is that preorders on average arrive between release day and 1 - 2 days afterward.
If you absolutely have to get it on release day, online preorder is probably not for you. Release day delivery is always strived for, but never guaranteed. Visiting a brick & mortar location is the best way to ensure you have it on release day.
