bootstrap datepicker https://docs.google.com/document/d/1UcKUJ6bsEXS0jD1yyVOFz2VHJCDjHmvSSKm0tGnm4Qo/edit#heading=h.el1l218u5pi3 code example

Example 1: date picker for bootstrap 4

<input class="datepicker" data-date-format="mm/dd/yyyy">

Example 2: date picker for bootstrap 4

$('.datepicker').datepicker({
    format: 'mm/dd/yyyy',
    startDate: '-3d'
});