Yes, i understand it, but how to make value visible by default?

Thank you for reply!

6) If I set input type date and set default value it won't show, why? How to fix it?

Snippet: https://mdbootstrap.com/snippets/jquery/p_manageroksoft-ru/2370964

Hi!

1) You can use some javascript or just plugin to validate your date input. The easiest way is something like this

$('#Birthday').on('change', function() {
  if ($('#Birthday').val() !== 'someRegexpCheck') {
    $('#Birthday').val('Choose proper date')
  }
});

2) You can't

3) Remove

    min: new Date(1910,3,20), //[1910, 3, 20],
    max: new Date(2020,8,5), //[2022, 7, 14],

in JS Object

4) You can't / It's just property that contains array with full names of weekdays, that date picker mechanism applies to HTML

5) Try to use this:

$('.fas.fa-calendar.input-prefix').on('click', () => {
  setTimeout(() => {
    const el = document.querySelector('.picker__title-display');
    el.textContent = $('#Birthday').val();
  }, 100);
});

Best regards