Time travel is a real thing in the Star Trek universe, and common enough that there is even a Temporal Prime Directive. Starfleet Academy has courses on temporal mechanics, and there have been multiple instances of intentional time travel. Each time someone takes a ship back in time via the slingshot effect, they have to perform certain calculations.
While Spock was the first (as far as I know) to formulate the math needed for the slingshot effect, is it now something that all Starfleet officers know? Are they limited to senior command officers? What's keeping rogue ships from traveling back in time?