> ## Documentation Index
> Fetch the complete documentation index at: https://adro.codes/llms.txt
> Use this file to discover all available pages before exploring further.

# Check if date is invalid

> Need to know if a date is invalid? Here's how.

```ts is-date-invalid.ts theme={null}
function isDateInvalid(date: Date): boolean {
  return Number.isNaN(date.valueOf());
}
```

The `new Date()` constructor will not throw an error if you pass it a wrong value, checking the value of the returned date object is the only way to know if the date is invalid.

```ts theme={null}
isDateInvalid(new Date()) // false
isDateInvalid(new Date('2023-55-99')) // true
```