I just added a date picker to the snippet section. One limitation of the IDEAScript dialog is that there is no date picker. I had recently seen a comment on the IDEA forum that they had a script for one but for whatever reason had not posted it in their script section. So I decided to try and create one of my own. I think the final product is not bad:
The code has an example of how to use it and access the dialog. The < and > will move you through the months. The year drop-down allows you to move in increments of 5 years forward and 5 years back.