I currently have my year end set to 31 March. I need to change to to 30 June, how do I do this?

You can change that in your Account settings, treasurer-bgswim. 

Let me show you the easy steps: 

1. Click on the Gear icon and select Account and Settings. 
2. From the left panel, choose Advanced and click on the Accounting section.
3. Change your accounting preference and click Save. 
4. Then, Done. 

You can also check this article for more information about year-end guide and checklist. 

Reach out to me if you have additional questions. I'm here to help!