Timer in process model

Can you clarify what you mean by "from 9 AM to 9 PM"?  What is your use case?  What actual behavior are you after? 

When we talk about using timers to trigger new instances of a process, for instance, we're talking about repeatedly launching that process at particular intervals (like hourly, or daily at 8 AM, etc).  This doesn't make very much sense when talking about a 12-hour timespan though, without further detail or info about the behavior you want to create.

Thanks for the reply.

We wanted to trigger process every 1 hour from 9 AM EST to 9 PM EST.

One pattern I see, is to trigger the process EVERY hour and then add a XOR to decide whether it is the right time to start. This is very flexible and can be controlled using constants or database queries.

You can also add conditions to the timer trigger to control this. You can also use constants, but just changing the constant will not change the behaviour of the condition. This would need a re-deployment of the model.

Then you will want to click the "Show Advanced Options" checkbox and enter an expression that checks to see whether the current time is within the current timeframe of that day.  I don't have that expression off the top of my head, however you should be able to formulate something using the Appian function library.

Edit: Stefan snuck in a reply before mine, but i can vouch for the approach he suggests as well - and that can be slightly easier to troubleshoot/test than using the Timer Conditions feature, to boot.