By default, the Year Start Date used for custom reporting periods is 1st January.
If your Year Starts on 5th April or any other date, you can set this date on the Targets page of a project.
Steps
Only Project Managers and Organisation Admins are allowed to access the project targets page.
Access the project targets page. You can do this by following these steps:
Select My Apps from the top menu
Select Projects
You arrive on the My Projects page
Find the project that you want to set targets for
Select the More Options button for that project
Select Targets
You arrive on the project’s Targets page
Press the calendar icon next to where it says Year Start Date
Either type in the new date or use the Date Picker by clicking the calendar icon
Scroll to the bottom of the page and press Save
You arrive on the Project page
That's it. You've successfully set the Year Start date for your project's custom reporting periods.