Contact Form 7 dropdown list first item

I presently have a dropdown list of dates with a preceding text ‘Select date (required). This works fine.

But … I don’t know if someone has selected the first item or not selected at all. The result is the same.

I want to put the text ‘Select Date (required’ as the first item.

Is there a way to show an error if this is not changed, that is, a date is not chosen?

Thanks