JSFiddle - React, Tailwind, and code Playground
by Dan Daniel
HTML
<div class="form-group">
<label class="control-label col-sm-2" for="date">Date:</label>
<div class="col-sm-5">
<input id="date1" type="text" class="form-control" name="training_start_date" value="">
</div>
</div>
<span> Diff from today:</span> <span id='diff'> - </span> <span> Days</span>
JavaScript
$('#date1').datepicker();
$('#date1').change(function() {
var diff = new Date() - $('#date1').datepicker("getDate");
$('#diff').text(Math.floor(diff / (1000*60*60*24) * -1) + 1);
});