ROSKILDE ON THE 4.TH of JULY?

On various web-pages it seems that the date for Prince's appearance in Roskilde is scheduled on the 4.th. - that is sunday, the last day of the festival.
Is this confirmed anywhere - Roskilde Festival communicates that a final plan for the four days will not be available until mid june...

Anyone have an idea - is it reasonable to buy a one-day-ticket for sunday?

Best regards,
David