what if i am interested in comparisons of less than a year 
you can compute month over month or quarter over quarter q q in much the same way as yoy indeed you can choose any time frame you desire the bottom lineyear over year yoy is a useful tool for financial analysts corporations and investors it allows for the comparison of financial figures from one point in time to the same point a year prior it paints a clear picture of performance whether performance is improving worsening or static this informs companies on how their business is operating and if changes need to be made it informs investors if their portfolio needs adjustment and analysts use it to describe the financial health of a company and make future predictions 