The night audit has not been run, so the hotel is still on that date
"… would be checked in on a day that is already over. Close the day first." Close the day, then check in.
The sentence: *The night audit for 25 Sep 2026 has not been run, so the hotel is still on that date. BK-1234 would be checked in on a day that is already over. Close the day first.*
Why: the hotel's business date is still yesterday. A guest checked in now would have their first night charged to a day that has ended.
Do this: answer OK to *Close the day now and check in?* if your login may close the day — the audit runs and the guest is checked in. Otherwise ask a manager to run it (Operations → Night audit), then check in.
See Closing the day: by itself, or by a person.