I am using "Webform Views Submitted Data" module to show webform submissions report with views. I have one expose filter name "Webform submissions: Submitted" which will give two date options; start date and end date. How do I select the date i want to filter by in a popup calender?
How about writing a custom jquery code with the help of http://docs.jquery.com/UI/Datepicker. I am not sure whether you are proficient with jquery , but still i would prefer to have a go at this.
We've been using Better Exposed Filters to have a datepicker in exposed filters. It's fairly straightforward to set up as well. This replies the first question you have, but I am unsure about how the Webform submission is affecting the scenario.