The */5 means "any minute, but every five".
Depending on the implementation, that’s enough
 */5 5-20 * * * php ~/pasta/para/app/artisan queue:work
Syntax of crontab:
*   *   *   *   *       caminho/comando
│   │   │   │   │
│   │   │   │   └────── em quais dias da semana de 0 a 7 (tanto 0 quanto 7 são Domingo)
│   │   │   └────────── em quais meses    (1 - 12)
│   │   └────────────── em quais dias     (1 - 31)
│   └────────────────── em quais horas    (0 - 23)
└────────────────────── em quais minutos  (0 - 59)
Specifying each item:
*        Todos
1,2,4    Um, dois e Quatro apenas
7-10     De 7 a 10, incluindo 8 e 9
*/5      A qualquer momento, mas com espaço de 5 (ex: 2,7,12,17...)
1-10/3   No intervalo de 1 a 10, mas de 3 em 3 (ex: 2,5,8)
Note: when you use /n, depends on when the cron is updated by the table that the range is counted, therefore, */5 can be either 0,5,10,15 or 1,6,11,16.
An example if it needed to be every 3 hours in that interval:
 */5 5-20/3 * * * php ~/pasta/para/app/artisan queue:work
Remark: the cron there are no intervals in some implementations (I don’t know if this proceeds in any modern distro yet), you may need to specify all hours:
*/5 5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20 * * * php ~/pasta/para/app/artisan queue:work
More details in the crontab:  
http://linux.die.net/man/5/crontab
							
							
						 
From what I see seems to be an application of Laravel, It would not be easier to use a Schedule and call the command ?
– Bulfaitelo
Laravel was just an example. The tags and the content of the question were in order to understand about cronjob itself
– Wallace Maxters