September can be one of the most useful months on the financial calendar. There is still enough time to change retirement contributions, prepare for holiday expenses, correct tax withholding, and deal with expensive debt—but the end of the year is close enough that you can see where your money actually went. Instead of waiting until December to discover that you’re short on cash or missed an opportunity, use the weeks before October as a financial checkpoint. You don’t have to complete a massive financial overhaul. Start with the areas where taking action before December 31 could actually change the outcome.