Is it possible to age / date a blood, semen or saliva stain?

Once a blood, semen or saliva stain has dried, it is not possible to accurately ascertain the time at which the biological fluid was deposited or transferred.

Is it possible to ascertain the details of an assault by the pattern on bloodstaining upon an individual's clothing?

It may be sometimes possible to ascertain from particular patterns of bloodstaining upon items of foot ware or clothing, (i.e. classic kicking or punching patterns) the actions of the wearer, or the positions relative to an assault.