I know it’s an accepted and even expected trope for time travel movies to go back in time to just moments before the event you’re trying to prevent happens, but if it was me I’d go back at least a few hours in time, factoring in things like traffic, the line at the Walgreens drive-thru, and, you know, having more time to be successfully preemptive. Changung the course of human history must not be rushed.