The Nokia Conversations website has just uploaded a teaser image and countdown timer that should result in an announcement this Tuesday.
The only thing other than the date that's given away is the "Green with envy" line and one saying "Summer brings out our inner glow".
While this is branded Nokia it's likely to be a Microsoft event since it now owns this area of the company – the area associated with phones.
This could be as simple as another Windows Phone, while the Lumia 930 is still not out yet. Some are suggesting there will be a new Android phone coming – perhaps a higher end version of the X Phone for everyone.
The final possibility could be the Windows Phone 8.1 Cyan update that's due out this summer. Although how the green chat fits in with this isn't really clear.
We're going to try and find out more before the European unveiling on Tuesday 24 June.