Workbook - Pensions Calc.xlsx

Hi

This is an inherited spread sheet and I've spotted a flaw that I'm not sure how to correct

Attached spread sheet has two tabs, Staff Data, Staff Costs

Staff Data lists Current Employees, date started etc and 'Pension' Contribution %

The Staff Costs tab has some formula in it which sums up Staff Data

Employees are only enrolled in the company Pension after completing 3 month probation period, therefore I need a formula that calculates from start date (col F) to insure it either falls prior to the month OR 3 month after in the relevant yr, i.e. 2014, e.g. All current employees who started 3 months before Jan-14 are entitled to Pension, any new employees will be entitled to the Pension 3 months from their start date

Any help would be grateful

Many thanks, Maddy