@reboot scripting not working when used in crontab

[wollik]

Hi forum members,
I need to run a script only once at boot or reboot.
Using the @reboot method in the crontab is not working under Armbian.

For example neither of these lines at the end of the /etc/crontab file is working:
neither

@reboot date >> /home/pi/boottime.txt
nor
@reboot /home/pi/control.sh  init >> /home/pi/init.log

Please has someone a hint how to get it to work under Armbian ?

Regards
wollik