website/examples-v8/InputTime.tsx

import { ChangeEventHandler, useState } from "react";

import { DayPicker } from "./react-day-picker-v8";

export function InputTime() {
  const [selected, setSelected] = useState<Date>();
  const [timeValue, setTimeValue] = useState<string>("00:00");

  const handleTimeChange: ChangeEventHandler<HTMLInputElement> = (e) => {
    const time = e.target.value;
    if (!selected) {
      setTimeValue(time);
      return;
    }
    const [hours, minutes] = time.split(":").map((str) => parseInt(str, 10));
    const newSelectedDate = new Date(
      selected.getFullYear(),
      selected.getMonth(),
      selected.getDate(),
      hours,
      minutes
    );
    setSelected(newSelectedDate);
    setTimeValue(time);
  };

  const handleDaySelect = (date: Date | undefined) => {
    if (!timeValue || !date) {
      setSelected(date);
      return;
    }
    const [hours, minutes] = timeValue
      .split(":")
      .map((str) => parseInt(str, 10));
    const newDate = new Date(
      date.getFullYear(),
      date.getMonth(),
      date.getDate(),
      hours,
      minutes
    );
    setSelected(newDate);
  };

  return (
    <>
      <DayPicker
        mode="single"
        selected={selected}
        onSelect={handleDaySelect}
        footer={
          <>
            <p>
              Pick a time:{" "}
              <input
                type="time"
                value={timeValue}
                onChange={handleTimeChange}
              />
            </p>
            <p>
              Selected date: {selected ? selected.toLocaleString() : "none"}
            </p>
          </>
        }
      />
    </>
  );
}