I've made a change to use this component with useForm. Here's the code — I hope it helps some developers working with useForm.

[im4nu]

First, this time-picker with date is awesome. The UX can be very improved using this component. Thank u Maximilian Kaske, Aaron Green, eliassebastian, Nicolas Cuellar Ochoa, Thibault Le Ouay, Ishan.

Now let me explain my usage.

// Using on main component

{...}
              <Controller
                control={control}
                name="endDate"
                render={({ field }) => (
                  <DateTimePicker
                    value={getElectionByIdQuery?.endDate ?? undefined}
                    onChange={field.onChange}
                  />
                )}
              />
{...}

// The modified component

"use client";

import { format, set } from "date-fns";
import { ptBR } from "date-fns/locale";
import { Calendar as CalendarIcon } from "lucide-react";
import * as React from "react";
import { Button } from "~/components/ui/button";
import { Calendar } from "~/components/ui/calendar";
import {
  Popover,
  PopoverContent,
  PopoverTrigger,
} from "~/components/ui/popover";
import { cn } from "~/lib/utils";
import { TimePickerDemo } from "./time-picker-demo";

interface DateTimePickerProps {
  onChange: (date: Date) => void;
  value?: Date;
}

export function DateTimePicker({ onChange, value }: DateTimePickerProps) {
  const [date, setDate] = React.useState<Date>();

  function toggleSelect() {
    if (!date) return;
    onChange(date);
  }

  React.useEffect(() => {
    if (value) {
      setDate(value);
    }
  }, [value]);
  return (
    <Popover
      onOpenChange={(current) => {
        if (!current) {
          toggleSelect();
        }
      }}
    >
      <PopoverTrigger asChild>
        <Button
          variant={"outline"}
          className={cn(
            "w-[280px] justify-start text-left font-normal",
            !date && "text-muted-foreground",
          )}
        >
          <CalendarIcon className="mr-2 h-4 w-4" />
          {date ? (
            format(date, "dd/MM/yyyy | HH:mm")
          ) : (
            <span>Selecione uma data</span>
          )}
        </Button>
      </PopoverTrigger>
      <PopoverContent className="w-auto p-0">
        <Calendar
          mode="single"
          selected={date}
          onSelect={(d) => {
            setDate(d);
          }}
          initialFocus
          locale={ptBR}
        />
        <div className="flex justify-between border-t border-border p-3">
          <TimePickerDemo
            setDate={(d) => {
              setDate((currentDate) => {
                if (!currentDate) return;
                if (!d) return;

                // console.log({ d, currentDate });

                return set(currentDate, {
                  hours: d.getHours(),
                  minutes: d.getMinutes(),
                });
              });
            }}
            date={date}
          />
        </div>
      </PopoverContent>
    </Popover>
  );
}