I agree, there should be a way to do this.
There is a useful plugin that does let you bulk edit the dates in course activities: https://moodle.org/plugins/report_editdates. It is only officially supportedup to Moodle 3.10. But if you have a newer Moodle, it may work fine. But it does dates only.
There is a useful plugin that does let you bulk edit the dates in course activities: https://moodle.org/plugins/report_editdates. It is only officially supportedup to Moodle 3.10. But if you have a newer Moodle, it may work fine. But it does dates only.