> ## Documentation Index
> Fetch the complete documentation index at: https://developers.lucca.fr/llms.txt
> Use this file to discover all available pages before exploring further.
# The leave resource
Absences from work, wether they are planned or not, are described in Lucca using three concepts : **LeaveRequests**, **LeavePeriods** and **Leaves**.
A **LeaveRequest** represent the request made by employees when planning time off. This resource is used for workflow purposes.
A **LeavePeriod** is the continuous period of absence requested by the employee or entered by HR. It is linked to a **LeaveRequest** if workflow applies.
A **Leave** is the subdivision of a **LeavePeriod**. There is one **Leave** per half-day of the **LeavePeriod**. Each **Leave** is linked to a **LeaveAccount**, which represent the type of leave (PTO, Sick Leave, Congés payés, RTT, etc).
There can only be one **Leave** per half-day. This prevents duplicates.
For **Leaves** expressed in hours (as opposed to **Leaves** in days), the duration of the **Leave** is stored in the value field of the **Leave**. The previous constraint implies that there can only be one type of **Leave** per half-day. This issue is solved in the next version of the API.