Teaching the same class this next phase how do I just change the dates for all assignment'
If you import your past course into a new shell, there is an option during the import to Adjust Dates. This does a fairly decent job, in my experience. You may have to go in and make a few adjustments, but with drag-and-drop on the calendar, this is easy. Here is a link that may help:
How do I adjust events and due dates in a course import?
And if you really want to get adventurous, here is are instructions for adjusting the grades all on one page:
Adjust All Assignment Dates on One Page
Hi Matthew Maher...
In addition to the great resources shared by Robbie Grant, I found this third-party LTI tool today that may be of interest (although, be aware there is a charge for this compared to what Robbie has provided for you): Edu App Center: Adjust-All HQ, by Etudes.
Hope this helps, Matthew.
Retrieving data ...