Add DateTime as hidden variable within form (change)

Add DateTime as hidden variable within form (change)

I am using "change" to serialize variables within a form

$(function() {
  $("form").on("change", function() {
    var s = $(this).serialize()
    console.log(s);
  })
})

I would like the form to include the DateTime as a hidden variable within the form (along with my other data).

How do i do this?