ko.types example

HTML

<script src="https://rawgithub.com/Knockout-Contrib/Knockout-Validation/master/Dist/knockout.validation.min.js"></script>
<script src="https://rawgithub.com/manuel-guilbault/ko.types/master/dist/ko.types.js"></script>
<script src="https://rawgithub.com/moment/moment/develop/min/moment-with-langs.min.js"></script>
<div>
    <input type="text" role="datepicker" data-bind="value: pay"/>
</div>
<div>
    <span data-bind="text: patInput"></span>
</div>

CSS

.validationMessage {
    color:red;
}

JavaScript

var viewModel = {
    date: ko.observable(moment()),
    pay: ko.observable().extend({type:number})
};
viewModel.dateInput = viewModel.date.extend({ convert: { 
    fromType: "moment", 
    toType: "string",
    format: "L",
    strict: false
}});
viewModel.formattedDate = viewModel.date.extend({ convert: {
    fromType: "moment", 
    toType: "string",
    format: "LL"
}});
viewModel.payInput = viewModel.pay.extend({convert: {
    toType: "string",
    decimals: 2
}});
ko.applyBindings(viewModel);