I Ching is used by various methods.
As one of them, there is a way that applies time, although time scale should be chosen as the situation demands. Of course, it is possible to apply our own birth date.
If we follow in the tradition, the lunisolar calendar calculated at each local time is used for this, not the solar calendar.
Here's an example: George W. Bush.
(born 6:26am July 6, 1946 / New Haven, Connecticut)
He was President of the 43rd United States of America, but led world countries to the Iraqi War. And I calculate the I Ching hexagram from his birth data: Nine at the top of the Hexagram 6 (Conflict).[*]
[*] According to his birth data, double hour is 5am to 7am(rabbit hour), but here I used 7am to 9 am(dragon hour). If the rabbit hour is correct, it will be Nine in the fifth place of the Hexagram 44 (Coming to Meet).
Study of the I Ching does not have the unitary way, but it is significant to apply time as a means of practice.