According to your company's policy, you can configure the rules accruing entitlement for your users.
There are two main ways it's usually done:
accruing rules based on a given day & month,
accruing rules based on the anniversary of the hire date.
In this article, we'll focus on the 2nd solution: accruing rules based on an anniversary of hire date, which is strongly connected with a carry-over policy (if applicable in your organization).
When you go to Configuration → Absence types → Choose certain absence type → Carry-over tab, you can choose the carry-over policy to be based on an Anniversary of her date.
The next point which is important to choose from is in the Accrual tab, specifically in each rule that is applied:
However, please note that this type of accrual affects the way that entitlement is presented to users.
User A was hired on the 1st of December 2021, and then, they gained 20 days of Annual leave.
Their next accrual will appear on the 1st of December 2022 on the anniversary of their hire date.
However, during the whole year (1.12.2021 - 30.11.2022), their entitlement will be presented as if they were still in 2021 (even if we are already in 2022).
That's because technically, they're still under the entitlement accrued on 1st December 2021. And this will remain this way up until 1st December 2022, when they gain new entitlement.
If you apply this policy for all users, it may happen that if you check their entitlement some of them will be yet in the previous year's entitlement (those whose anniversary hasn't occurred yet this year), and others' entitlement may be presented already in the current year (if their anniversary has already occurred by the day you're checking the entitlement).