Just in case you missed Eamonn's earlier post here, this will just be a rehash of that. Powell will be delivering the opening/keynote speech, which is expected for about 25 minutes, at 1405 GMT. That will be one to watch alongside Lagarde's address at 1900 GMT, so just about an hour before the market close.
Here is the link to the full agenda: Jackson Hole Economic Policy Symposium: Structural Shifts in the Global Economy