Input validation

Problem/Motivation

Please add input validation.
It is not permissible for the start date to be greater than the end date.

Steps to reproduce

When entering a start date greater than the end date, the facet disappears, as well as its dependencies, and it is necessary to reload the page by going back a step and correcting the input data. The same occurs with an empty result, ie. when there are no events between the start and end dates.

Proposed resolution

It would be desirable, before sending the data, to check whether the start date is less than the end date, and in case of an empty result, there should be an option to reset the facet, i.e. the user can clear the start and end date.