Air lets you track as many types of time off / absence as you'd like.
When creating or editing a policy you can select the types you want to track. For example, you can track Holidays (Vacation), Sick days, Personal Leave, Training Days, Compassionate Leave, Flex-time, etc.
To create a new time off type:
Go to the Time off App, then select Settings from the left hand menu
Choose the policy you want to add a time off type to.
Select Types and Rules
Scroll down and click Add time off type
This will create a new time off type with default settings. Click the pencil icon to edit settings for this type.
Your new type will automatically become available to all employees assigned to the time off policy.