Trying to add years to a date field for PTO Accrual Tracking

I have an HR report I'm trying to replicate in QB that exists in Excel currently. We have a standard PTO Accrual tier based on an employee's hire date. As they reach these milestones, HR modifies their accrual rate in the HR system. They track a list of employee's and hire dates in Excel and have to manually review the list. I'm trying to build this feature in QB and leverage the Notifications so that they're alerted when they need to address a PTO accrual change.
In Excel, I'm able to add years to a date field but in QB I'm only able to add Days (that I can tell). When I add days, I'm off a few due to leap years and what not. I know my formula isn't the most efficient way to go and certainly didn't know if there is a way to more accurately increase the Years on a Date field.