Start by opening the CONFIGURATION MENU by pressing on the configuration button in the top right.

Then select COMPANY SETTINGS to open your company configurations. 

Once in the edit menu, you can choose the first fiscal year for which you want to build your budget in the field “First year of your budget" and save your change.

This choice determines the end of the fiscal year of your first budget year. For example, if your fiscal year ends in March and you choose 2018 as the first fiscal year, your first budget year will be April 2017 to March 2018.

Related Articles (Please refer to the links below)

-How to change the year-end (end of the fiscal year) of a company?