Is it permissible to specify a time for birth in the Istikhara prayer?

Istikhara prayer was legislated for permissible matters, not for foreknowledge of the unseen. Attempting to know the time of birth through it is an attempt to know the unseen, and this is exclusively Allah's domain. Claiming knowledge of the unseen leads to apostasy and is a denial of the verses of the Holy Qur’an.