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To perform .xml export, log in as a Jira administrator user and click cog icon (1). After selecting "Add-ons" (2), head to "Export Scheduled Issues (43).
You can export (34) Scheduled Issues from all projects (it is set as default) at once, or export it only from selected projectsones. (After you click on any of existing projects, "Export type" automatically switches to "Export Scheduled Issues form selected projects only".)
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