The feedback that you’ve given here or through other channels has been invaluable in informing our product planning.
For scrum projects, you will see the stories/tasks and dependencies, where the start/end dates are aligned to the sprint dates. This follows closely with the scrum framework, where work is scoped to be delivered within the timeframe of a sprint. https://support.atlassian.com/jira-software-cloud/docs/schedule-work-for-scrum-teams-on-your-roadmap/
For Kanban projects, this is currently not possible to show the explicit dates for the child issues. We are currently working on a solution in BETA. Only participants in the current BETA group have the ability to schedule stories/tasks using explicit dates for Kanban projects. Please keep in mind that planning and scheduling issues from the Roadmap not only affects the Roadmap view, but also flows onto the board and backlog. We are gathering the feedback from the wider BETA group to make sure that the dates set, do not impact the development team's existing processes within Agile.
We hope to make this available for all Kanban projects on all editions of Jira Software Cloud (including free and standard) in the next few months.
If you would like to provide specific feedback or chat over a zoom call about your team needs, then feel free to email our team at: firstname.lastname@example.org
Rathesh | Product Management, Roadmaps.