In order to rely on this information you need to do couple things:
1. add your outlook account to WF
https://experienceleague.adobe.com/docs/workfront/using/basics/home/use-home-area/configure-home-cal...
2. place your tasks manually on to your schedule
As a result hours will be calculated with a split as per below screenshot:
grey - sum of hours for outlook meetings/ appointments
blue - sum of hours for tasks you placed on the schedule.
Planned hours, logged hours are not used here. Which is a shame, especially when you think about planned hours. There are number of ideas in the community about updating that integration, but I don't think WF is does care much about until they deploy redesigned Home Area (later this year)
