Search Date with Datepicker

Good Evening

I’m trying to change the default Date Search filter “Today, Tomorrow, This week …” to a one datepicker “from date”. I’m struggling to make it work. I’m not sure how to get the data from the datepicker to be able to compare it with the _event_start_date therefore i’m asking if it is possible to do so?

Thanks

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