timezone is not set in recalbox.conf. I found a way to set to Brazil.
1 - Remount your / filesystem to read-write
mount -o remount,rw /
2 - Unkink the /etc/localtime since it is set to Europe/Paris
unlink /etc/localtime
3 - create new symbolic link to Brazil/Sao_Paulo
ln -s /usr/share/zoneinfo/America/Sao_Paulo localtime
And finally type date to see your new timezone
date
Thu Sep 15 17:27:03 BRT 2016
Hope this helps.