If you regularly work with scripts on any Unix or Linux platform and it gets killed when you logout from ssh, the session dies or the scripts stops working after x time then you need to deown it and force it to the background.
So instead of running
/your/script/filename
run
nohup /your/script/filename &
What this does is start the script, the nohup deowns the scripts (meaning that it has no owner so you can logout without killing the process) and the & at the end sends the process to the background. This is the alternative method to run something from within screen but this version works good with a crontab.
FYI the crontab is a file and a program (both named the same) that executes commands (opening files, sending email, any command that you could do via the regular shell) at specific interval or times.