I want to format a date string but for all other strings just return that input. Now when the input is a string that contains any number e.g. "You are number 1", the string is parsed as a valid date "1 Jan 2001".

const value = new Date(input);
if (!(value instanceof Date && isFinite(value as unknown as number))) {
  return input;
}
// format date and return

How can I check if that string is really a string containing just a number or a date as string? The input date string might always have the same pattern but ideally it shouldn't matter.