The mfg will tell you up to 1 day before. I doubt anyone has even come close to that.
But, people will certainly have ideas. It is a very aromatic oil. I imagine you could smell/taste it for days. But if I leave it out in a cup for example, it won't have any detectable smell after a week. The oils seem to be pretty volatile.
I don't use it past the second week of flour myself. If I use anything beyond that it would just be spinosad, which is a short lived bacteria and not harmful to people.