Feature idea: manually selected date

[elislaats]

Is your feature request related to a problem? Please describe.
A project detail page shows a date on which the project was uploaded or edited. However, for some projects it could be useful if they have a manually selected start- or end date.

Describe the solution you'd like
Research if this would be a useful feature. If so, design how it for the detail page, editing view, wizard and maybe overview.

Additional context
This was suggested in a usertest that can be found here