Adding 1 to Date while binding using KnockoutJS
One way would be to move the date display logic to your view model.

function vm(){
    var self= this;

    self.TimeByDay = ko.observable(new Date("December 17, 1995 03:24:00"));

    // fn extention of ko.observable        
    ko.observable.fn.AddOneDay = function(){
        return new Date(this().setDate(this().getDate()+1))
    };

    self.AddOneDay = function(TimeByDay){
        return new Date(TimeByDay().setDate(TimeByDay().getDate()+1))
    };
}


And then in your view you can have

&lt;span data-bind="text: TimeByDay"&gt;&lt;/span&gt;
&lt;br/&gt;
&lt;span data-bind="text: AddOneDay(TimeByDay)"&gt;&lt;/span&gt;


Or

&lt;span data-bind="text: TimeByDay.AddOneDay()"&gt;&lt;/span&gt;


Use the extention fn method if your application requires 1 day added to date frequently. Read this for more.

Jsfiddle: https://jsfiddle.net/newuserjs/oLh6u67z/4/