yes, it does cause an error, and no, it's not a bug.. If the time difference is just a few hours, it corrects if for you and continues to boot. If the time difference is fairly large, then you must correct it manually by running a full filesystem check.
If you really really want to force it to not error like that on boot, there are 2 options you can try.
1: add the fastboot
option to your kernel line
2: If you really want to be able to set your system clock massively behind your filesystem, you can set
broken_system_clock = 1
in /etc/e2fsck.conf and it should skip that check.
My advice.. Don't use either one, fix your filesystem and leave the system time alone
And the answer to travelling and crossing the international date line?? Set your clock to UTC, that doesn't change no matter where you travel to.. Then change your local time zone and let the system convert it for you.
This behaviour is intended to make the system fool proof
If you are foolish enough to want to corrupt your filesystem with the wrong date, then it requires your to fix the problem.. Thereby making it fool-proof