The present continuous is used to talk about arrangements for events at a time later than now. There is a suggestion that more than one person is aware of the event, and that some preparation has already happened. e.g.
I'm meeting Jim at the airport = Jim and I have discussed this.I am leaving tomorrow. = I've already bought my train ticket.We're having a staff meeting next Monday = all members of staff have been told about it.
The present continuous is used to talk about arrangements for events at a time later than now. There is a suggestion that more than one person is aware of the event, and that some preparation has already happened. e.g.
I'm meeting Jim at the airport = Jim and I have discussed this.I am leaving tomorrow. = I've already bought my train ticket.We're having a staff meeting next Monday = all members of staff have been told about it.