... but first I'll set the scene.
.On my site, the Parent Page is a summary of a programme of planned events; each Child page contains the detail of each event. They all need to be pre-scheduled to automatically appear on the same date on a date in the future; 01/07/2018 as it happens to be next
The main issue (ver 2.2.1 - 2.3.4):
When a page is either "Draft" or "Scheduled" that page does not show in the list of possible Parent pages. This makes it impossible to set everything up ahead of time as it really needs to be published. It actually makes the point of scheduling pages for future publications, well, pointless, with child pages involved. One might as well leave everything as a draft until such time as it is needed. It means not setting up the child-parent relationship, but waiting until the future date arrives, letting it become visible to the public as separate unrelated pages, and then going back in to point the child pages to the Parent page.
Allow any page, whether scheduled or published to be selected as a parent page.
It might also make sense to add the rule... so long as the published date/time of the child page is after the parent page... but I'm not so bothered about this as the menu hide child pages until the parent is visible.
Secondary issue (ver 2.2.1 - 2.3.4):
When the published date is set in the future with the intention of scheduling it and it is saved as Draft when the status later changes from Draft to Published the published date/time changes to now. This means that it goes live immediately and is not scheduled. You have to then immediately re-set the desired scheduled date/time.
Whether this is by design or a bug, can I ask for pages with a scheduled future publish date/time to be allowed to be set as a parent page?