Show badge if DateTime Item is from today

Hi there,
I have a calendar view as an UI widget where I would like to always show an orange badge with “today” when the starting date is on the actual day.

badge: '=((items.Kalender_Result_0_Begin.state.isToday() ? "Heute" : false)'

How should the real condition look like? Sure isToday() is not working. But I also have no clue how the correct condition would look like.


looks like: