When I retired, I was at the point where I got 4+ weeks of vacation - 4 weeks for 20 years service, and then 1 additional day for each year over 20. The company I worked for did not allow you to carryover unused days (except in extenuating circumstances) into the next year, and if you didn't use them, they were lost. I don't know of anyone there that never used all of their days that they were entitled to. I sure used mine!