Provide an additional option on the bulk change date action that allows you to move start and/or end dates forwards or backwards by a number of days.

This feature request was discussed in the community forum: https://community.atlassian.com/t5/Advanced-Roadmaps-questions/How-to-move-multiple-epic-1-week-forward/qaq-p/1642306

According to @Dave Draper, someone in the AR team has already played with this functionality.