Dojo implementation of the "improved user interaction with XPages date picker" script (jQuery) by Marky Roden (src: http://xomino.com/2012/03/14/improving-user-interaction-with-xpages-date-picker/). This uses pure Dojo (which can prevent the need to load another library, if you're already using Dojo). This is used and tested with Dojo v. 1.6.1. …

calPickerImprover.js

/*
 * Dojo version of the improved behavior of the XPages calendar picker.
 * Adapted from the jQuery version, originally by Marky Roden.
 * credit: http://xomino.com/2012/03/14/improving-user-interaction-with-xpages-date-picker/
 * Adapted by Eric McCormick, @edm00se, http://about.me/EricMcCormick
 */
dojo.addOnLoad(function(){
	//id has _Container and is class of xspInputFieldDateTimePicker
	var myAr = dojo.query("[id$=_Container].xspInputFieldDateTimePicker");
	//iterate over each element to apply affect
	myAr.forEach(function(node, index, arr){
		//current root node, based on id$=_Container
		var curNode = node;
		//span for the button to fire the picker
		var myBtn = dojo.query('> span > span > span.dijitButtonContents',curNode)[0];
		//actual <input> element into which is focused/typed
		var myInputFld = dojo.query('> div > div.dijitInputField > input.dijitInputInner',curNode)[0];
		//connect the focus event to the picker click event
		dojo.connect(myInputFld,"onfocus",function(){myBtn.click()});
		//provide an onkeypress preventDefault
		dojo.connect(myInputFld,"onkeypress",function(evt){evt.preventDefault()});
	});
});