# Script musts start with:
#!/bin/sh
# Allow execute grant on it
chmod +x /bin/sh/myscript.sh
# Edit crontab:
crontab -e # open user crontab in edit mode
i # for insert. Make your changes
0 2 * * * /bin/sh myscript.sh # plan it daily at 2am for example
:wq! # quit and save