This is how you can add a unique unavailability on Voilà! .
Audience: Administrator, Supervisor, Manager, Employee
1. Navigate to the Voilà! web console d
2. Click on your profile picture.
3. Select MY PROFILE.
4. Click on the three dots icon next to Availability. 
5. Select Add unique unavailabilities.
6. Select the desired date(s).
7. Click on Add (x) unavailability.
Download as PDF: How to add a unique unavailability