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Duration field derives its default value from Extended settings in the chart configuration when no duration is specified for the task during its creation. It
On Cloud, Duration is stored internally and doesn’t have a corresponding custom field in Jira. However, it can be shown on the issue details page by means of Start field and End field specified in the chart configuration.
In Data Center version, Duration has a corresponding Jira field which is added to the project screens by default.
For charts based on agile scheduling mode, duration is an internal field. Duration of tasks is derived from duration of backlog and sprints they belong to.
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