If, like me, you are using your existing screens and controllers with 12.04, there is a missing javascript file framework/images/webapp/images.calendar1.js and the associated calendar.html files.
Your controller.xml will have a <handler name="screen" class = ...HtmlScreenRenderer"> That particular file (HtmlScreenRenderer.renderDateFindField() generates html code that calls javascript:call_cal(document...) and that javascript code is in the above named javascript file. I am not sure when this changed all you have to do is put these two files back in your images folder and make sure they are loaded by GlobalDecorator. Currently, screens in the Ofbiz code are rendered with a MacroScreenRenderer which use jQuery to render the date-time widgets. I am going to change my screens to use this renderer as time permits. I did not write a Jira on this as it is not an issue with ootb Ofbiz, only for applications that use HtmlScreenRenderer to render screens. BTW, I get more and more impresseed with this code the deeper I get into it. Skip