In Chronoforms8 you can control the limits between which the calendar is allowed to select dates, here is how to do this:
ChronoForms v8
Easy to follow tutorials for ChronoForms8, the Joomla & WordPress form builder
How to use custom JavaScript or PHP validation in your form
in ChronoForms v8 you can validate field values using PHP or JavaScript functions, here is how to do it:
How to export saved form data to CSV

Here is how you can export stored form log data to a CSV file
How to use PHP data anywhere in your form

In ChronoForms 8 you can run PHP code, capture the results in a variable then use the results in later actions or views in your form using the {var:php_action_name}, here are the steps to do this:
How to delay the redirect in your form
In Chronoforms 8 you can delay the redirect to allow for other actions to complete before the redirect is started.
How to use your own HTML code in ChronoForms
Add custom HTML to your Chronoforms using the HTML view
How can I create a calculation security question in Chronoforms8
Add a simple math check to your form for extra security against spam bots
How to add a confirm popup to a submit button?
How to setup ReCAPTCHA in your form in ChronoForms8

How to customize the uploaded file name
How to save and view the form data in Chronoforms8
How to write a full custom SQL query in Chronoforms

How to create a Joomla contact form using Chronoforms 8 in 3 minutes

Adding a contact us form in Joomla or WordPress is straightforward with ChronoForms8, a versatile form builder that creates custom forms with email functionality. This step-by-step guide shows you how to build a Joomla contact form that emails form submissions to the site admin, and how to use ChronoForms8 in WordPress too. We’ll also introduce ChronoMails, an extension for advanced email management.
For a detailed overview of ChronoForms8, check this official tutorial.
How to use ChronoForms 8 - Introduction

ChronoForms 8 has a much simpler and easy to use interface than previous ChronoForms versions, in this tutorial we will explain the new ChronoForms v8 interface.
Note: a newer more detailed Visual tutorial of how Chronoforms8 works is here