title: Office 365 default Calendar's ID changes automatically
body: <p>I was using V2 DLL of Office 365 API for performing calendar operations.
  I am saving default calendar's ID for performing operations on it.</p>
  
  <p>It was working fine for me from last two years but lately since last 1 month, when I am trying to fetch calendars from my account - just to check if the calendar is available on whom I am trying to work on - the calendar ID fetched is different from the calendar ID fetched from O365 API </p>
  
  <p>Saved Calendar ID - <code>AQMkADc5NDI0NjFXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX8jvkC_BGp2m1nqTgcABqRbG9B8nEivpWgOOBcJGwAAAgEGAAAABqRbG9B8nEivpWgOOBcJGwABH-QZPwAAAA==</code></p>
  
  <p>New Response -</p>
  
  <pre><code>[{
      "IsBooking": false,
      "IsAdditional": false,
      "CalendarName": "Calendar",
      "CalendarId": "AQMkADc5NDI0NjFXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX8jvkC_BGp2m1nqTgcABqRbG9B8nEivpWgOOBcJGwAAAgEGAAAABqRbG9B8nEivpWgOOBcJGwABHKkz6wAAAA==",
      "Selected": false,
      "IsDefault": true,
      "HasWriteAccess": true,
      "IsFreeBusy": true,
      "EWS_URL": null,
      "CalendarColour": "#5D61DF",
      "TimeZoneId": null
  }]
  </code></pre>
  
  <p>However the change is not permanent and after a day or so, when tried again, the calendar id changes back to same id saved in db as default calendar id.</p>
  
  <p>The ID of calendar is calendar's unique identifier. However in many cases, it's value is changed. Is there any way by which we can identify the same calendar using changeKey? Any idea how we can use changeKey property?
  <a href="https://i.stack.imgur.com/Lsva5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Lsva5.png" alt="https://msdn.microsoft.com/en-us/office/office365/api/complex-types-for-mail-contacts-calendar#CalendarResource"></a></p>
  
  <p>I find it strange too but only last 30-35 characters changed for calendar id. May be something wrong with encryption algorithm.
  Please suggest.</p>