The official program for the World Meeting of Families can be found in the link below. It includes the opening ceremony on August 21st, the congress in the RDS from August 22nd to 25th August. There will be a Festival of Families on Saturday evening 25th of August and the World Meeting of Families will conclude on the Sunday, 26th of August, with a closing Mass.
All details of the official program can be found on the World Meeting of Families website at WMOF Program
If you find all the details for purchasing tickets for the World Meeting of Families by clicking on the following link: World Meeting Tickets