Hi @zlamalp,
I have to tell you that my solution is not really working.
Indeed, when I gave you my answer, I've forgotten that I had changed the way I create the /sbin/sogosync file.
In fact, after the creation by running the original script, I modified this file manually in console mode :
sudo mount / -o remount,rw
sudo vi /sbin/sogosync
Then I edited the file in order to fit with the following lines :
export DISPLAY=:0.0 && export DBUS_SESSION_BUS_ADDRESS="$(ps -u phablet e | grep -Eo 'dbus-daemon.*address=unix:abstract=/tmp/dbus-[A-Za-z0-9]{10}' | tail -c35)" && /usr/bin/syncevolution data_base_name
Note : in the above line data_base_name is to be replace by the name of your database.
Then at each execution by cron daemon, the string DBUS_SESSION_BUS_ADDRESS is evaluated.
It would be nice if the original script would be able to put this line in the file itself but I'm not an expert in shell programming so I've no solution to propose.