How can I make my button Today button work?

Question

    const changeCurrentDay = (day: { year: number; month: number; number: number | undefined; }) => {setCurrentDay(new      Date(day.year, day.month, day.number));}`

   const changeCurrentDay = (day: { year: number; month: number; number: number | undefined; }) => {
    setCurrentDay(new Date(day.year, day.month, day.number));
  }

  const nextDay = () => {
    setCurrentDay(new Date(currentDay.setDate(currentDay.getDate() + 1)));
  }
  const currently = () => {
    setCurrentDay(new Date(currentDay.getFullYear(), currentDay.getMonth(), currentDay.getDate()));
  }

and

    <button onClick={previousDay}><FontAwesomeIcon icon={faArrowRight} rotation={180} /></button>
    <button onClick={currently}>TODAY</button>
    <button onClick={nextDay}><FontAwesomeIcon icon={faArrowRight} /></button>

I've tried to

   const currently = () => {
    setCurrentDay(new Date(currentDay.setDate(currentDay.getDate() + 0)));
  }

And the one listed above to help avail.

Thanks for any help :^)