May I propose an alternative workflow to achieve what you are after?
- Keep the Event Topic as the ‘anchor’ and make it clear in the text that it is provisional, or maybe keep a wide swath of time
- In the OP (or a subsequent post), create a poll with the options available for times using the Insert Date functionality
- Once the poll has closed, edit the date/time of the Event to match it.
- If additional events are needed, make them closed topics and refer them to the ‘anchor event topic’.
What do you think?