Setting up new company - GL

We are setting up a  new company.    For GL, we set up the Account balances as of December 31, 2017.

 It looks like the General Ledger is no longer in "SET UP" mode.

The other modules are still in set up mode.

Is there a way to change the current month in BW back to December 2017, rather than May 2018.

Or do we have to Recreate the GL file?