According to its official website Rihanna will perform at the Peace & Love music festival in Sweden. We don’t know what day she will perform.
Peace & Love is the largest festival in Sweden and the only one with an outspoken message of Solidarity, Diversity and Understanding, which runs through the whole event. It started in 1999 and is located in Borlänge, Sweden. The festival is a part of an organization which is involved in other projects besides the festival in Borlänge. It takes place from  June 26th to June 30th.

You can buy tickets here.