Bone meal is supposed to supply both Calcium and Phosphorus in soils that are deficient in them. But that depends on many factors including how active a Soil Food Web the soil has.
Most soils have adequate levels of Phosphorus and seldom need additions, although those with a vested interest in selling you something you do not need will tell you differently. How do you know that your soil needed P added? What did a good reliable soil test tell you about that? Who did the soil test?

Here is a link that might be useful: About soils need of Phosphorus

Because it is an organic supplement, it is naturally slow acting and releases phosphorus over a period of time. The complete effect would be closer to the 6 month mark than anything else.

The advise to test before applying is sound. Most soils do contain adequate levels of P and lack of blooms may be more likely attributed to excessive amounts of N from your previously applied ferts rather than insufficient P.

I know, and thanks, I guess I can't expect anyone to just tell me about bonemeal without commenting on my soil or my garden. I just wanted to skip the "why are you using it", but really my particular garden excluded, generally, in any garden, how long does bacteria take to turn bone meal into 15P. I mean, I wish I could find the answer on some kind of chemical site, but I've found nothing. I just want a dry, to the point answer... if you take some soil from anywhere, add dirt, add bone meal and add water, assuming that there's bacteria in the soil which let's just not be difficult about that and assume there is, how long does the process take. thanks :)

You received your answer.......it is NOT fast acting so allow about 6 months. You are not going to get anything more definite than that as there are too many variables involved to be precise - soil temperatures, pH levels, irrigation (both natural and manual) frequency, existing populations of the organisms necessary to the break down the bone meal, etc.

As to not commenting on your soil and the need for testing, you should be aware that unless you have correct info on your current soil status - achieved only via testing - bone meal may take even longer to react properly, if at all. That's why any sort of definitive answer is impossible to provide.

To elaborate a very little bit on the above really good comment from gardengal, bone meal and other mineral supplements are always long term remedies for problems, but one thing that will make that long term even longer is soil pH. If yours gets up in to the mid sevens, mineral breakdown and uptake rates get clobbered bigtime.

You might check your pH or even (at the least!) do an acid fizz test before exploring other causes of deficiencies, and I never suggest pH tests, but this could be key.

Contact a soil professional at a local college/university or at a soil testing lab or a soil consultant.

The reason for asking about soil tests and why you think the soil may need something is because often soils do not need that supplement. One reason many states, today, ban P in fertilizers is because excess P is causing major problems in the lakes, algae growth.
The nutrient levels in my soil has gone from low optimum to high optimum without the use of things such as Bone Meal, or Rock Phosphate, or anything else other then organic matter.

Bone meal can have very high levels of fluoride in it. I wouldn't use it for that reason. Fluoride is very dangerous. There are several very good books on the subject. It accumulates in the body, especially in the bones, and that's why bone meal can have such high quantities in it.
Fluoride Alert

This post was edited by magnetico on Sat, Aug 16, 14 at 23:06

I've asked you before where you live in Canada but you never responded. Here in Saskatchewan, everyone's crops are late because of the cold spring and cold, wet soil. If your plants are healthy, I'd avoid messing with them and just let them do their thing. There's still time, you can always throw a row cover or light blanket over them when the first frost hits, to prolong the ripening season.