datetimepicker value is always true

Hi,

I've made a datetimepicker with a checkbox in it. Datetimepicker is intended as a filter - the user enters the date and gets filtered the data for that date. dtp is without binding.

The problem is there, if the datetimepicker checkbox is empty, it still retains the value.
Currently datetimepicker constantly feeds value to the database.

So I thought, is that a validation problem or only the properties, but in my case I added checked = true and showcheckedbox = true also or need to looking somewhere else.