This is what I do for unix:
in the command prompt type “crontab -e”
this puts you into a cron text file in the default text editor. Mine is vi.
Then on the first line you schedule the script ie:
“0 12 * 2 2 sh /home/user/script.sh”
the first number is the number of minutes past the hour
the second number is the number of hours ie 12= noon.
the third number is the day of the month
the fourth number is the month of the year
the day of the week ie sun=0
you can subsitute each number with a * as a wildcard.
The above example scheduled the script script.sh at 12 noon, every tuesday in february.