max hours cap for accrual

Have a customizable max hours cap for accrual E.g. Accrual on a fortnightly basis and employees can accrue and bank up to 160 hours, once they have reached 160 hours of accrued time, they forfeit any further accrual until they take time to reduce their balance below 160 again. With regards to the accrual, a user can bank up to 160 hours, but if they take 20 hours, they can then accrue another 20 hours and once capped again accrual stops again until they are below 160 again. This is cyclical.