I would like to setup 2 alerts whenever no hits during the period . one is peak hours from 6am-01am and another one is non peak hours 01am-6am
each alert should trigger every 30 mins during these period .
let me understand: why do you want two alerts if you have to check that you haven't logs in a period?
you could have two alerts if you have a different threeshold in the two periods, but you have to check only if there are logs, so I think that you don't need two alerts.
Anyway, if you want two alerts, you have to follow two times this procedure:
If you want two alerts, the only difference between them is the cron expression and/or eventually the message in the eMail: