Q:

Microsoft Graph API and shared calendar permissions

I'm using the Graph Explorer on developer.microsoft.com to query shared calendars. 
Example:
https://graph.microsoft.com/v1.0/users/user@my.com/calendarview?startdatetime=2018-04-19T19:25:06.250Z&enddatetime=2018-04-26T19:25:06.250Z
This works fine on calendars where I have Reviewer or Full Details access. Calendars where I have Free/Busy, subject, location, I get a 404 and response like this:
{
"error": {
    "code": "ErrorItemNotFound",
    "message": "The specified object was not found in the store.",
    "innerError": {
        "request-id": "9f9e950f-038e-4411-b813-10a76d4b94fa",
        "date": "2018-04-19T19:42:48"
    }
}

}
I can open the same calendar with my Outlook client no problem. 
My question is, are all of the different permission levels that you see in the Outlook client not supported by Graph? Or is there something I'm doing wrong?  

A:

The permissions are consistent with Outlook and Exchange Web Services the difference is when you have "Free/Busy, subject, location" (or even one of the lesser) you only have rights to view the FreeBusy data of the Mailbox you don't have permissions to query the calendar directly which is what your trying to do so the error your receiving is consistent with that fact (and is what you would see in any of the other API's). Outlook (since 2007) uses the getuseravailability when querying the FreeBusy data for a user (which is where that right is valid) the equivalent in graph would be findMeetingTimes https://developer.microsoft.com/en-us/graph/docs/concepts/findmeetingtimes_example 
 https://graph.microsoft.com/v1.0/me/findMeetingTimes

(I don't think this is quite there on feature parity with EWS and Outlook on FreeBusy data though but its getting there) 

