How can I set my form so you can vote only once per day and it resets each night?

I can see how to limit response to one, but I want that reset each night so they can vote again tomorrow, possible? It used to be but I can't find the option anymore.

Unfortunately there is no default option to achieve your requirement. You can set your form so that users can only vote once, however there is no option to reset it aside from deleting the first submission so they can submit again.

A possible workaround I can suggest would be to add a Unique Question on your form that is based on the email or name of the user, plus the current date. To achieve this, please follow the guide below:

1. Add the email or name field. In this demo, I am using email as part of the unique question.

2. Now add a hidden date field and set it to Current date.

3. Then we add a textbox field. This is where we will combine the email and current date, and we will use this as the Unique Question.

4. Now we can add the Update/Calculate condition below. Here's a guide that can help: How to Insert Text or Mathematical Calculation into a Field Using Conditional Logic

5. Finally, go to your Preferences and select Advanced, and set Unique Text as the Unique Question. You can also follow our guide here: How to set Form Limits Based on a Unique Question

Save the changes, and you're all set. If the user tries to submit the form with the same email on the same date, then they will be unable to submit the form. But if they use the same email on a different date, then they can submit the form successfully.

Here's the demo form so you can test it out: https://form.jotform.com/62900221448954 

I made the date and unique text visible for demo purposes, but you can hide these fields on your form. You can clone the form to see my setup.

Please let us know if you need further assistance.
Regards.