i made a function that will take the date and then change it to a string, however typescript says that it is possibly null, how would i make typescript happy.

i am using MUI date picker and recoil, i want to push the date to a global state to use for later

```
 // Start Date

  const [startDate, setStartDate] = useRecoilState(StartDateState);

  const [value, setValue] = React.useState<Date | null>(
    new Date("2014-08-18T21:11:54")
  );

  const handleChange = (newValue: Date | null) => {
    setValue(newValue);
    setStartDate(newValue.toString());
  };

```

error above = (parameter) newValue: Date | null Object is possibly 'null'.ts(2531)

My Atom is

```
export const StartDateState = atom({
  key: "StartDateState",
  default: "",
});

```

My ui that i want to show it in is

```
 const date = useRecoilValue(StartDateState);

  Start Date : {date ? date : "No Start Date"}

```

So in total i want to push the date to a global state and use it somewhere else.