Confirm - How to extract the street works Duration Days

Product Feature: Street Works

This cannot be extracted direct from the Confirm database.

This field is calculated dynamically and not saved in the database, hence will not be retrieved by just selecting the "sw_notice_header.duration_days" field.

This is calculated by working out the difference between 'Work_start_date' and 'work_est_end_date'/'work_comp_date' to get this value. 
UPDATED:  April 10, 2017