Time travel necessitates both an origin and a destination. In space this is coordinated with events, as a "mother ship" can be stabilized in a fixed location relative to any planet.
Time itself becomes one; the singularity of past, present, and future in a moebius ribbon of time as a world of consciousness. Traversing time must be a controlled effort of both the means and ones own individual consciousness, else the individual entity may be discorporated from its body and "lost in space".
The training for time travel is in a minimum of two parts. First and foremost is the same training exercize as befits the use of both a teleportation system and a portal.
What was known in religion as meditation becomes the means of conscious control in scientific endeavors. Meditation is a series of explorations in and around ones own being until a knowledge of ones own "self" (previously known as the divine self) is mastered.
Without a mastery of ones own self, Time is not a valid concept for travel in space.
Specific meditations allow for traversing both Time and space while "awaiting" the arrival of ones own physical body (as in teleportation). Preparing for entry through a portal need be precursed by the training (meditation) necessary to bring to mind immediate recall of the outcome of such meditation.
To program a specific "place", or places can be figured mathematically as each plane of existence is relegated from within unto 3 points generated upon a "sphere" of infinite points. As all existence is in motion, the moebius ribbon of time becomes relevant only within the physical existence, thus the individual must return to his physical body wherever it may be sent.
The mathematics may be found in the following universal structure: Math of Time and Time Travel Math