Hello penguinresort,
Welcome to Community! Reconciling your accounts in QuickBooks Online ensures your books are up-to-date. When you're not able to enter the statement ending date, there are a few ways to bypass this. I would be glad to help!
Initially, I suggest clearing cache on your browser , if you haven't done so already. Then sign into QuickBooks Online using a private/incognito window. If you experience the same issue, try another browser such as Firefox, Edge, Google Chrome, or Safari. If you still can't enter an ending date, click on the Calendar to select the date from there. In addition, if you see the option to Resume reconciling, click on that. In the upper right-hand corner, hit Edit Info. Make the necessary changes then select Save.
Should the issue persist, the best course of action is to contact our Customer Care team outside of Community. With your consent, they can work with you in real-time and ensure you're able to reconcile your account as soon as possible!
Feel free to reach back out, if you have any other questions. We would be happy to assist!