How to auto-populate original estimate field based on two date picker fields?

Summary

How to auto-populate the Original estimate field based on two date picker fields on any Jira issue?

We will make use of Automation for Jira to achieve this use case.

Solution

1. Let's assume there are two date picker fields available on the issue screen namely start_date  and duedate. To calculate Original estimate we need to find the difference between the duedate and start_date field. Every time start_date or duedate is edited, the rule should recalculate the Original estimate on the corresponding issue. To achieve this, here are the steps we need to follow:

   1. Navigate to Project Settings > Automation and click on the Create Rule button.

   2. Select the Trigger as Field value changed  and put start_date  and duedate  under Fields to monitor for changes  box.

      

   3. Then under action, select Edit Issue and choose the field Original Estimate  from the dropdown. Set the expression below

      1 {{start_date.diff(duedate).days}}d

      Feel free to refer to Jira smart values - date and time.

   4. Now, add or edit the start_date or due date fields on any issue, and the Original estimate will be calculated automatically based on the difference between these two fields.

      

   5. Rule details and execution will look something like below: