You have to undo the reconciliation and redo it, using the correct date.
Resolution for 'correct date issue: 'How do I change a wrong reconciliation ending date?' available: Yes.
The correct date issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the correct date issue yourself by looking for a resolution described in the article. If it is a complex correct date issue or you are unable to solve the issue, you may contact us by clicking here or by using other correct date support options.
For more information about resolving issues related to correct date in Quickbooks/QBO or to get support for the issue 'How do I change a wrong reconciliation ending date?', click the link below: