How to validate Date of Birth in javascript with input[type="Date"]?

Question

I know there are a few questions out there on this topic, but they all are either unclear or, they are using input[type="text"] in them.

In my HTML form I have an input of type date. So now I want to make sure that the date of birth is valid(Date is not in the future!). How do I do this?

What have you tried so far? [You are expected to have made an attempt](https://meta.stackoverflow.com/questions/261592/how-much-research-effort-is-expected-of-stack-overflow-users) — Taplar, Jul 10 '19 at 19:24
Make a Date instance from it and compare that to `new Date()`. `>` and `<` comparisons work the way you'd expect for dates. — Pointy, Jul 10 '19 at 19:24
So what is different with reading input text value and a date input value? — epascarello, Jul 10 '19 at 19:26
There are many great libraries out there for working with dates, for example, https://momentjs.com/ - have you tried using something like this. — katamaster818, Jul 10 '19 at 19:29
Consider using the [`min` and `max` attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/date#Additional_attributes). — showdev, Jul 10 '19 at 19:32
There's a whole section on [validation](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/date#Validation) in MDN's documentation of `input type="date"`... — Heretic Monkey, Jul 10 '19 at 19:40

score 0 · Accepted Answer · answered Jul 10 '19 at 19:41

The comments have suggested a number of approaches, but for the specific functionality you're implementing, most of them are overkill. This only requires a simple comparison operation.

document.getElementById("check").addEventListener("click", function(e){
  // Create a date variable which stores the current day at 00:00 local time.
  let today = new Date();
  today.setHours(0,0,0,0);

  // Parse the provided date in the default YYYY-MM-DD format.
  let birthdate = new Date(document.getElementById("birthdate").value);

  // Check whether the provided date is equal to or less than the current date.
  if (birthdate <= today) {
   document.getElementsByTagName("span")[0].textContent = "Valid!";
  } else {
   document.getElementsByTagName("span")[0].textContent = "Invalid!";
  }
});

<input type="date" id="birthdate"/>
<button id="check">Check</button>
<span></span>

StackOverflow is not a code request site. Answering questions that do not follow the community guidelines promotes more questions like this in the future. — Taplar, Jul 10 '19 at 20:10

How to validate Date of Birth in javascript with input[type="Date"]?

1 Answers1