If you need an easy way to change the dates for multiple activities (i.e. Assignments, Quizzes, Forum etc...), you may use the Dates feature in your Administration block. This is especially useful if you are importing a course from a previous quarter and you need to update the dates for the activities of the course to the current quarter.
1. In your course site scroll to the Administration block, click on the Reports tab, then select Dates.

2. In the subsequent window select the activity type from the drop-down that you would like to change the dates for.

3. Click on the Expand all below the drop-down menu.

4. You will then see the Activities and dates for the course displayed and you can then make the necessary changes to the dates.
5. Once you've made the necessary date changes scroll to the bottom of the page and then click on Save changes.