This question me happen too.
I'm use ln -sf or cp or nano for /etc/localtime,but all is nothing happen.
so we know this files just a RAM image files.(if power off,file is missing,after next start read from image)
change file is impossible,but......have any can change files we can try it,right?
So,I'm use half day time for find and try,at last,I'm find it.
have a files,at /recalbox/share/system call the "recalbox.conf",you can use putty and nano it.
find "# ------------ F - Language and keyboard ------------ #",at end have a character string:
bingo,we find it.what's mean?when system is boot,print this for make /etc/localtime.If change it,like:
at next boot,time is Russian/Moscow.If they are "Asia/Tokyo",at next boot time is Japan/Tokyo.
So,you just at /usr/share/zoneinfo/ find where you are,and change string,at next boot time is on your set.
My English is not good,don't mind,and enjoy yourself.