JAVASCRIPT

check if date time string is invalid date js

const isValidDate = function(date) {
    return (new Date(date) !== "Invalid Date") && !isNaN(new Date(date));
}

js check if date object is invalid

const isValid = !Number.isNaN(new Date(timestamp).getTime())

detect invalid date js

isNaN(d.getTime())

js check invalid date

const validDate = !isNaN(Date.parse('foo'))

new date javascript invalid date

if (Object.prototype.toString.call(d) === "[object Date]") {
  // it is a date
  if (isNaN(d.getTime())) {  // d.valueOf() could also work
    // date is not valid
  } else {
    // date is valid
  }
} else {
  // not a date
}