This KB explains how to use the Exchange Online Appointment SmartObject, specifically the List Suggested method.
Make sure you are using the Exchange Online Service Instance before generating your SmartObject:
Execute the List Suggested method:
This is how to enter the values correctly:
The following results will be returned:
Please note: The Start and End dates are NOT the dates for the meeting, but rather the dates within which users are available. You cannot specify time along with the Start and End dates, when using this method. The End date must be at least 1 day after the Start date. Do not add time as the default is 12:00 AM for both.
If you do enter it incorrectly, the following error message will appear: