JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <input type="text" data-bind="value: text" style="width:250px;"/>
</div>
<div>
    <input type="button" value="Place current date" data-bind="click: placeDate"/>
</div>

JavaScript

function ViewModel() {
    this.text = ko.observable();
    this.placeDate = function() {
this.text(new Date().toLocaleString());        
    }
    this.text.subscribe(function(newValue) {
        alert('Text is changing to ' + newValue);
    });        
}
ko.applyBindings(new ViewModel());