Is it possible to prevent form submissions with less than 48 hours notice before date of event?

Is it possible to prevent form submissions with less than 48 hours notice before date of event?

You can disable your form on specific date. Please check Disable on date part of this guide:

https://www.jotform.com/help/137-How-to-limit-submissions-in-a-form 

This can be used if you have one event on your form and event date is fixed. 

However if your users are selecting event day and if you want to prevent them to submit your form if selected event date is in less that 48 hours of current date, then I would suggest you to use two DateTime fields, form calculation widget and conditionals logic. 

This guides can help you to set this inside of your form:

How to Perform Calculation in the Form?

How to Show or Hide Fields Base on User's Answer

Here is my demo form: https://form.jotform.com/62585776639980 

Feel free to test it and clone it. 

Note: you can hide Current Date and calculation fields from the form, so that your users can not see them.

Hope this will help. Let us know if you need further assistance.