Hi Michdel,
Please refer below query
JQuery
$(function () {
// You need to mention the textbox names on which you want to apply datepicker.
$("[id*=FirstTextBoxName],[id*=SecondTextBoxName]").datepicker({
showOn: 'button',
buttonImageOnly: true,
buttonImage: 'Image/calendar.png'
});
Hope this works for you