Hi peter-werner,
This can be done by adding in a new Leave Category to account for the extra accrual. You would then edit the Employee settings to use Category on their Anniversary Date:
1. From within your QuickBooks Online Company select Employees
2. Navigate to Payroll Settings then choose Leave Categories
3. Select Add
4. Enter the settings you require for your second Leave Category and Save
Note: You can make bulk changes to Employee's Leave Categories by using Leave Allowance Templates.
For more information please refer to this article: https://support.yourpayroll.com.au/hc/en-au/articles/200265754-Leave-Categories
Please feel free to reach out if you have any other questions!
Rebecca