If they have the root access typically needed to reboot a server1 they could also just wipe the logs without rebooting.
1: GUIs typically have a way to reboot without such privileges, but those are typically not installed on machines just used as servers.
Assuming they went to signed 64-bit time, it should be about 3:28:32 pm UTC on Sunday, December 4, 292277026596. Yes, that last number is a year.