Can't change checkbox checked status simultaneously

Question

When I check the checkbox for 'Monday', the 'Tuesday' checked status is updated. It works well simultaneously.

But, once I click to check or uncheck 'Tuesday', and if I then check 'Monday', the 'Tuesday' doesn't change status as same as 'Monday' anymore. After checking/unchecking 'Tuesday' it doesn't sync with the 'Monday' checkbox.

$(function() {
  // main product upload
  $("#monday").change(function(e) {
    $("#tuesday").attr("checked", this.checked);
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<input type="checkbox" id="monday" name="monday">
<input type="checkbox" id="tuesday" name="tuesday">

Answer 1

Use prop instead of attr.

$(function () {
    // main product upload
    $( "#monday" ).change(function(e) {
        $( "#tuesday" ).prop("checked", this.checked);
    });       
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>    

Monday: <input type="checkbox" id="monday" name="monday" > <br/>
Tues: <input type="checkbox" id="tuesday" name="tuesday" >