How can program at crontab dayly each 30 minut
Try this first:
man crontab
Regards
Like this !
00,05,10,15,20,25,30,35,40,45,50,55 8-16 * * 1-5
Every 5 minutes between 8 and 16 o'clock on monday 'til friday
In your case .
00,30 8-16 * * 1-5
Regards