Changing a not-for-profit Financial Year end in Reckon One?

Hi, We are running a not for profit community event organisation in NZ, and have just completed our first year. When I go to run the reports, it shows the year as April to March. Our main event is at the start of April, which means we have most of our income before that and most of our expenditure in April. According to the reports, we would owe tax for last year, and need to make a huge claim for this year. We cannot do that. I'd like to run the financial year in ReckonOne according to our company financial year. How can I change that please? Is that the Book Start Date in Settings? Thanks in advance for your help.