Salary Forecasting - Anniversary Date

Hello all,

I'm trying to put together a 3 year payroll forecast that will calculate monthly salaries, raises and bonuses based on anniversary dates . ie + 12 months from first activity.

For example someone hired in May 2015 wouldn't see their increases kick in until May 2016.

I've attached a sample of what I'm working with. Right now it's calculating increases based on calendar year end but I'd like to change that.

Any help would be appreciated.

Thanks in advance.