Displaying an event before date is finalised

Wondering if it is possible to add a "Date to be advised" option to allow the display of events prior to a confirmation of the date?
The date could perhaps be displayed as "TBA" or "TBC" until finalised?
Or even if we could display the month only that would also be good.
At this point the system does not allow the display of an event without a date, unless there is a workaround? 

I use 31-12-2099 for this.
I change the text string to what i would like.
I have one site wit 'future date...'
I have one site with 'Online course'

Thanks Joris, I have looked into adding a long-term future date but then the date still shows in the modules of upcoming events, either as the full date or (worse) the date and month eg DEC 31 depending on the module, so good idea but not an ideal workaround.

I am not sure if it works in all modules but it should.
If you have an override remove that for a moment to test.
If not is is a bug you can report to Tuan