JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can use the Limit Date feature for the standard date picker, this will allow you to specify dates to exclude from the calendar selection.
This guide will provide you with more information regarding this feature.
Do let us know if you will need further clarification on how to use this feature.