It would be better to add programs to these directories:
/etc/fcron.cyclic
/etc/fcron.daily
/etc/fcron.hourly
/etc/fcron.minutely
/etc/fcron.monthly
/etc/fcron.weekly
fcrontab might be updated during a core update. The above directories won’t be updated.
See: My fcrontab file has been replaced by a new one - #11 by jon