The concept of "time-traveling hackers" refers not to literal time travel but to a sophisticated cyberattack technique where hackers manipulate a system's internal clock to bypass security measures.

Even when checking an outside master clock, computer software will introduce additional distortions. The operating system typically digests network packets in batches, delaying time packets.

While the computer clock is not required to be set correctly, I would still interpret this to mean that the gmt_unix_time is supposed to match whatever the internal clock is set to, not be ...

How to Get In-Game Events Early by Changing the Date on Your Nintendo Switch Manually adjusting your Switch's system clock can help you unlock time-specific content and circumvent in-game timers.