Any page can be scheduled to appear between certain dates. Once scheduled the pages will only be visible for participants between the starting and ending date.
Administrators will be able to view the page from Action Menu > List all pages at any given time.
The scheduling can be removed by deselecting the Schedule when page is visible in the menu from the Page settings > Advanced settings.
The exact time of day cannot be scheduled, only the day(s) the page will be visible.
This is because in real life it is really hard to predict unpredictable things; a workshop might be running a few minutes late, a participant is slower at answering and needs some more time...
This the page will be visible for the whole duration of the day and become available at midnight and be hidden one minute 'till midnight.