Ours is really similar to Countrigal's:

Timesheets are electronic. I can type in my code and see how much sick leave and vacation leave I have banked. I also type in the leaves that I take. Leave time accrues so much every pay period (depends on how long you have been with the company as to how much accrues each period).

Vacation time banks up to a maximum limit, then the timesheet automatically sends me an electronic reminder to "use your vacation soon or risk losing it." When I retire or am laid off, I am paid for unused vacation time.

Sick leave has no maximum accrual; we can convert sick leave to vacation leave but don't have to (I'm banking all mine for extra maternity leave for when I decide to have children); we do not get paid for unused sick leave when retired or laid off.