On/Off time(datetime field) doesn't cleared after cancel button is pressed

I open page properties and fill some fields



After I pressed cancel button, and reopened properties dialog, all field cleared, but datetime fields didn't.



What is the rigth way to clear datetime fields?
Best How To:
I was debuggin and find out strange behavior of isApplyDefault method in \ibs\cq\ui\widgets\source\ext\override\widgets\form\Field.js. It is compare created and modefied date, if they equals returns true, otherwise false.

I just ovveride method processRecord in DateTime.js to remove calling isApplyDefault:

processRecord: function(record, path) {

    if (this.fireEvent('beforeloadcontent', this, record, path) !== false) {

        var v = record.get(this.getName());

        if (v == undefined && this.defaultValue != null) {

               this.setValue(this.defaultValue);

        }

        else {

            this.setValue(v);

        }

        this.fireEvent('loadcontent', this, record, path);

    }

}

in Field.js it is:

processRecord: function(record, path) {

    if (this.fireEvent('beforeloadcontent', this, record, path) !== false) {

        var v = record.get(this.getName());

        if (v == undefined && this.defaultValue != null) {

            if (this.isApplyDefault(record, path)) {

               this.setValue(this.defaultValue);

            }

        }

        else {

            this.setValue(v);

        }

        this.fireEvent('loadcontent', this, record, path);

    }

}