I used to be able to schedule a site workflow to run hourly between 6 AM and 6 PM every day. I am not seeing how to do this anymore. Is this capability still available? If so, how can I accomplish this? If not, when did this change, and why?
I would suggest confirming exactly what version you're on.
I'm on SharePoint 2013 and Nintex 2013, and here are my options for scheduling a site workflow:
From what I can tell, the only option to limit the the hourly runs are by workday. So, by checking the Workdays Only checkbox, the workflow will only run Monday through Friday.
Now, if you're talking about a flexi task within the workflow, you might want to look at this question that was already answered: