To add an absence for one or multiple days in Yearly View, go to View - Yearly View (for adding absences in Yearly View in Team Manager, see Add Multi-cell Absences in Yearly Overview in Team Manager). Select the cells you want to add absences for and click Actions -Add absence (or right-click - Add absence):
Adding bookings for multiple days in Yearly view in Astrow Web
Add/Edit absence window opens, and you can add the absence for the days selected.
For more details related to absence time types, see New/Edit Absence.
The functionality of self-adding absences for multiple days is available only with an ESS license and the Self Edit Absences permission. It is also very important to set in Configuration - System - Application config the maximum days for self-edit bookings/absences for the past and future.
For more details related to the number of days in the past/future to edit absences, see System Settings.