It has been almost officially confirmed when the 2019 Worldwide Developers Conference will take place.
McEnery Convention internal document shows several reservations for a particular room, including that of Apple for an event scheduled for the evening of June 6 and dedicated to WWDC 2019 . A similar event was organized last year too, for this, starting from the history of previous Apple conferences, start and end dates should be June 3 -June 7.
Last year, the inaugural keynote that WWDC opened was on Monday, June 4 and this year it seems it would be June 3, which is the first day of the event.
Of course, you have to keep in mind that those dates have been officially confirmed by Apple. But if we pay attention to what happened last year, we can say that they will be very close if they are not really what has been predicted since the second and fourth weeks of June are completely discarded due to the already announced conferences from other companies.