In Data Monitoring Alarms, you can now monitor over the midnight period. This means that you can monitor from 9PM to 5PM the next day; you will get an informational message as this. This is new in the v8.6 version.
But still we have the limitation that the end period cannot be lesser than 15m. You will get this Error Message then.
Note: The monitoring over the midnight period in Data Monitoring Alarms can be done only if you use the option 'Daily' as for weekly or Monthly. There is ambiguity as the day will overlap to the next day, which may have not been selected as the day for monitoring. For weekly/monthly we have conflict in setting it across days.