Excel model - Financial Analysis

Dear All,

I would like to kindly ask for your assistance on a bottleneck that i am facing the last couple of weeks in excel and can't solve myself. I have attached a simplified version of my model just for illustration purposes in order to make it easier for someone that could assist me. So basically, as shown on the tab "Financial1" of the excel file my current model refers to company financials that have a financial year starting from January & ending on December. Filling my full model based on that is pretty straightforward and easy. However, certain companies on my portfolio do not have a financial year of January to December but March to December or October to September. Can someone help me build inside my already existing formulas another formula that takes that into account and depending on each case adjusts the dates shown to e.g., March to December or October to September?

Many thanks in advance!