I am reconciling and put the wrong ending date in and reconciled the account now my date is off. How can I go back and change the date?

It's good to see you posting here in the Community forum, lstruckingcfo.

I'm here to provide some information regarding the wrong ending date for your reconciled transactions. 

Changing the ending date for the completed reconciled transactions isn't an option. To correct it, here's what you'll need to do:

• Leave the date as it is and just make sure to select the correct end date the next time you reconcile (an incorrect date doesn't affect any balances and will not prevent you from future reconciliation). 
• You can undo the reconciliation and then reconcile with the correct ending date.

Additionally, I'd like to share an article with you that will help you resolve any issues you might encounter if QuickBooks doesn't match your bank statement at the end of reconciliation: Fix issues at the end of a reconciliation in QuickBooks Online.

If you have any concerns regarding reconciliation, please feel free to let me know by commenting below. I'm always here to help you out. Have a fantastic day!