QuickBooks asks many questions when you set up a company. Many have default answers that a person may accept at the time, but later realize are incorrect. Changing the information after the fact is thankfully not difficult. For instance, it's easy to change from a calendar year to a fiscal year.
Open the QuickBooks file.
Choose "Company" from the menu across the top of the screen.
Change the fiscal year end. Once you choose "Company" from the top menu, the "Company Information" screen automatically opens. On this screen, in the lower-left corner, there is a section called "Report Information." In this section the first month of the fiscal year for book and tax can be adjusted. If the business files taxes on a calendar year but uses a fiscal year for book purposes only, change the fiscal year only and leave the tax year as "January." If the company also files taxes on the fiscal year, change both the fiscal year and tax year months.