%{trigger.version.startDate}
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When cast to text, the output depends on the jira.date.time.picker.java.format
parameter set in your Jira instance.
19/Mar/20 1:38 PM would be returned for dd/MMM/yy h:mm a
This field code is only available for JWT automation rules since several events can trigger the execution of a rule.
Automation-only field codes can additionally retrieve information from the trigger event (e.g. the version being updated, the user triggering the event, etc.)