To me, the best option is to create your view on the SQL management studio taking into consideration all the required data you want, then get the view published to Smart list builder as mentioned above by Mr. Jeff.
Although, you can still use a various functions in Smart list builder to manipulate the data as requested. A list of functions (including Date functions) is illustrated in the knowledge base article below;
In addition, you may refer to the article published by Dynamics GP Support and Services blog on the link below;
Calculated Fields in Extender and the Builders
Hope this helps out in your inquiry,