A tarot reading is just a snapshot in time. It reflects what is happening around the querent in the present. It may also indicate what past influences are at the root of the present situation, and it might also show a possible path to the future. However, nothing is set in stone, and the querent might make changes in the present that affect how things turn out.
For instance, if you had a reading and the reader told you that your future planned trip isn't such a good idea, you might decide to alter your plans and go on a different trip, or not go on one at all. You are in charge of making the changes that will define your future experience.
My readings have been very accurate many times, and a large reading, such as a ten card Celtic Cross might take a year to unfold.