Nope, you can only have one year end in a fiscal year.
SOP is to create a new company with the new year end, retain the original as is for historical reporting purposes.

There are a couple of year end utilities that allow you to change the year end, they shift all transactions by x periods to align with the new year end.

Musick International has a Year End Change Utility. This will allow you to change to a new year end.
www.musick-int.com/.../FiscalYearEndChange-Instructions.pdf

By definition, you can't have a year end without creating opening balances for the next year. If you just need to zero out all Income accounts to Retained Earnings, a journal entry would definitely be the best approach.

If there isn't an appetite to create such a JE from a Trial Balance manually, as I see it, there are a few options:
1. Export the TB to Excel and format into a JE import file
2. Write a macro to browse all income accounts from GLAMF
-for each account, lookup the balance at your cut-off and create a line in your JE
3 Read the balance of your JE and create a final entry to the Retained Earnings account.

Best of luck!

The Fiscal Year End Change does all of this and more including all sub-ledgers.