So just to clarify if the employee has been there LESS than 1 year the vacation time is ZERO, After exactly 1 year they are entitled to ONE week and you want a cell next to their name in a separate column that says "1 Week" until their anniversary date (current year) then you want that cell to return to ZERO ?

Or do you indicate when they have taken vacation time (say in August) and the cell goes blank until their anniversary date the following year

When do they get 2 weeks or 3 weeks, is it after 3 years or 4 years or something ?