execute cron job in every a few minutes, hours

• execute the cron job every 5 minutes:

  */5 * * * * /path/to/script.sh
  

• execute the cron job every 5 hours:

  0 */5 * * * /path/to/script.sh
  

• execute the cron job every Friday:

  0 0 * * 5 /path/to/script.sh