/etc/crontab:
min   hour   day   month   week   user   command

# set hardware clock:
   hwclock --systohc -u

# reset password in /etc/shadow
   delete the sign between the first and the second colon (:) with an editor, save and reboot
   exclamation mark (!): password is locked
   empty: no password is required

# add new line at specific position
   sed -i '90 i host   all   postgres   0.0.0.0/0   trust' /etc/postgresql/16/main/pg_hba.conf
   -i                                                        creates a temporary file, which replaces the original file
   90                                                      line number
   i                                                         insert on or more lines before the 90.
   host   all   postgres   0.0.0.0/0   trust   text to insert
   /etc/postgresql/16/main/pg_hba.conf   file to insert this

   a    insert one or more lines after the 90.
   $a  insert a new line after the last