All events on the map

Hi,
I have an option that an event can be “open by appointment” (in danish “Efter aftale”)
And I want the events the have checked this option to also be shown on the map.. meaning an event that does not have dates but have the option “Efter aftale” to show on the map.
Is that in any way possible?

An example event is this one:
http://langelandskkunst.dk/events/denmark/langeland/tranekaer/kunsthandvaerk/nielsen-og-woldike-glas/

An alternativ could be to have all events in the database to show on the map… Can i do that?

Thanks,
Marie