You can accrue 1.5 times your yearly total, then you stop accruing. So, say I get 100 hours per year. I can bank up to 150, then I stop earning vacation time until I use some.
For team leaders:
Up to 5 years=2 weeks
5 to 10 years=3 weeks
10 to 25 years=4 weeks
25 plus=5 weeks