How can we set carryover for leaves for certain duration(for e.g. 3 Years)

Summary:

The business requirement is to create absence plan in such a way that at the beginning,

1) Employee receives 36 days sick leaves for 3 years

2) After 3 what ever they have left will be deleted

3) New amount will be given of 36 days

Content (required):

No carry over after 3 years, the carry over is after the first year and the second year

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):