There is no 'set' latest date. On one occasion, at least, I removed a super of honey in November, but that was exceptional. Seasons are not as predictable as in the distant past, I think.
Location, weather, need for treatments or feeding, etc can all make a difference. I don't generally bother too much with extracting until September. But, there again, I don't rob them of everything and they generally don't need feeding and just some rearrangement of stores between colonies - particularly at uniting time - is all that is necessary. One and two colony beeks clearly do not have the flexibility afforded to those with multiple colonies, so fixing dates is not something beekeepers should be doing.
Location, weather, need for treatments or feeding, etc can all make a difference. I don't generally bother too much with extracting until September. But, there again, I don't rob them of everything and they generally don't need feeding and just some rearrangement of stores between colonies - particularly at uniting time - is all that is necessary. One and two colony beeks clearly do not have the flexibility afforded to those with multiple colonies, so fixing dates is not something beekeepers should be doing.