I have made a feature request in the past to be able to schedule the availability of a form. This comes in handy with schools for example that can only make enrollment forms available at a specific time.

With the new Forms Designer and the new Field Rules capabilities, this might be able to be solved in an easier way. If an additional option for a field rule could be based on a date and time, we would be able to accomplish the previous request. As an example, you could create 3 sections on the form. One section would contain all the fields that the end user would need to fill out. The second section would contain a custom HTML field with a message that registration has not yet opened and will be open on X at X. The third section would contain a custom HTML field with a message saying that registration is currently closed.

Using a Field Rule that can utilize date and time values, I could have a field rule that shows section X based on if it is before or after X date and X time to show the appropriate section.