I use a Manual trigger to test the following Automation rule:
Log message: days differance: {{issue.customfield_13081.diff(issue.customfield_13080).days}} days
In the Audit Log I get:
days differance: days
Seem like the calculation return Null value.
customfield_13081 is Plan Target end field and customfield_13080 is Plan Target start field.
Any experaince/advice with this diff calculation - eventauly I need the diff to be an intiger days value