deactivation of client side validation onclick

At the linked page I added a javascript calendar into a CF7 form and nearly everything works very well.

But if one clicks on the yellow toggles of the calendar to hide/show the calendar`s sidebars it fires the CF7 client side validation, although I wrapped to whole form into a <div class=”novalidate”>…</div>

It looks like the novalidate-class has no effect.

Do you have an idea, how the can avoid this behavior of the form?

Thank you very much and best regards.

Ralf

The page I need help with: [log in to see the link]