Hi there!
We are currently trying to set up a rule for automatically updating sub-task due dates. The tricky part is that the date fields in question are two custom fields, both date pickers, format is as such: 01/Jan/18.
Example:
- Parent task's due date is originally 1/Jan/18
- It gets updated to 1/Feb/18
- When the issue is edited, I would like the rule to update some sub-task due dates to 1/Feb/18
- Ideally, I would like to make some due 30/Jan/18, as they need to be done a bit ahead of other tasks.
However, I cannot get it to work, even without the date adjustments.
What I attempted to do, for a test rule, was:
- Manual Trigger
- Branching For Subtasks
- Edit issue fields
- Field to update: customfield_1
- Copy customfield_1 from Trigger Issue
This rule runs successfully, but the sub-task due date for this field is never updated. What am I missing? I am very much a greenhorn in this circuit, and fully understand I might be missing something basic, so any assistance is welcome. 
Thank you for reading!