public function withDateTime(\DateTimeImmutable $dt): self
    {
        $obj = clone $this;
        $obj->_dateTime = $dt;
        return $obj;
    }
public function withDateTime(\DateTimeImmutable $dt): self
    {
        $obj = clone $this;
        $obj->_dateTime = $dt;
        return $obj;
    }
public function withDateTime ( \ DateTimeImmutable $ dt ) : self { $ obj = clone $ this ; $ obj -> _dateTime = $ dt ; return $ obj ; }
Get self with reference date and time.

@param \DateTimeImmutable $dt
@return self
Get self with reference date and time .