Can I preset my form to be enabled at a certain time and be disabled at another time?

It is possible to disable the form on a certain date and time. Here's a guide:

1. In the Form Builder, click the Preferences button.

2. Under the General tab, you'll the see the Status drop down. Click it and select the Disabled on Date option. After that, set the Date, Time and the Warning Message.

Here's the complete guide: https://www.jotform.com/help/137-How-to-limit-submissions-in-a-form

Let us know if you need further help. Thank you.