All day event dates incorrect in calendar ListItems created in Graph API

[mikepowell]

Category

• Question
• Typo
• Bug
• Additional article idea

Expected or Desired Behavior

When creating an all-day calendar ListItem, the start time should be 00:00 on the start date, and the end time should be 23:59 on the end date.

Observed Behavior

The resulting ListItem starts at 00:00 on the day before the expected start date. The end date and time are as expected.

Steps to Reproduce

POST https://graph.microsoft.com/v1.0/sites/root:/{sitename}:/lists/{listname}/items

// Single day, all-day event on 8/31/2018
{
    "fields": {
        "Title": "Test Event",
        "EventDate": "2018-08-31T00:00:00",
        "EndDate": "2018-08-31T23:59:00",
        "fAllDayEvent": true
    }
}

Result

"fields": {
    "EventDate": "2018-08-30T00:00:00Z",  // A day earlier than expected
    "EndDate": "2018-08-31T23:59:00Z",
    ...
}

Note that the results are the same if EventDate and EndDate are specified with no time information, e.g. "2018-08-31".

Workaround

Adding a day to the EventDate field causes the created item to be correct. This works even if creating a single-day event, where it's necessary to specify a start date that's later than the end date:

{
    "fields": {
        "Title": "Test Event",
        "EventDate": "2018-09-01T00:00:00",  // Add a day.
        "EndDate": "2018-08-31T23:59:00", 
        "fAllDayEvent": true
    }
}

"fields": {
    "EventDate": "2018-08-31T00:00:00Z", // Correct!
    "EndDate": "2018-08-31T23:59:00Z",
    ...
}

Related StackOverflow question here

[jxnx888]

Hello @mikepowell , could you please tell me what's your language of this code? Like C#, JavaScript? TypeScript? Or Json Body?

[mikepowell]

The code in the issue text is portions of request and response bodies in JSON format. (I tagged the code blocks as JavaScript because I wanted to add comments, which aren't technically supported in JSON.)

As far as the issue itself I discovered it in C# code that uses the .NET Graph API, but have reproduced the issue using raw REST requests in Graph Explorer.

[jxnx888]

For now, one of the workarounds is changing the "fAllDayEvent" to "false".

[mikepowell]

Yes, that works but does not create an all-day event of course. My requirement is to have these events displayed in SharePoint and Outlook as all-day events rather than events with start and end times.

[tigertop]

I can confirm that same behavior on our tenant, but it works correctly on our client's tenant. Our tenant was created like a year ago and is on the fast track. Client's tenant was created like 1.5 months ago.

[tvkit]

Did you try specifying midnight as the end point?

For example, in C# ?

var start = when.ToUniversalTime().Date;
var end = start.AddDays(1);

The delta on (end - start) is one day, not one day plus a nanosecond for example. So I'd expect this to work for an all-day event.

When specifying 11:59 PM as the end point, the All Day calc may be subtracting 24 hours from the end point going back to the previous day. Just a thought.

[svwerner]

The same problem appeared today then creating a new calendar event via MS Graph API. Now 2 days are beeing substracted from the EventDate submitted. Disableing the all day event resultet in a substraction of 1 day of the submitted date.

The request has been made with an app registration using the Microsoft Graph API Endpoint for SharePoint Online.

POST: https://graph.microsoft.com/v1.0/sites/{sitename}/lists/{listId}/items

Body

{
   "fields": {
      "ContentType": "Ereignis",
      "Title": "SharePoint Date Bug",
      "EventDate": "2020-01-03T00:00:00Z",
      "EndDate": "2020-01-12T23:59:00Z",
      "Description": "",
      "fAllDayEvent": true,
      "fRecurrence": false
    }
}

Response ( .. only the field data is shown here)

{
    "fields": {
        "@odata.etag": "\"97070c93-8810-4c6c-b86c-61df55d12a0e,1\"",
        "id": "90",
        "ContentType": "Ereignis",
        "Title": "SharePoint Date Bug",
        "Modified": "2020-01-10T05:17:57Z",
        "Created": "2020-01-10T05:17:57Z",
        "AuthorLookupId": "1073741822",
        "EditorLookupId": "1073741822",
        "_UIVersionString": "1.0",
        "Attachments": false,
        "Edit": "",
        "LinkTitleNoMenu": "SharePoint Date Bug",
        "LinkTitle": "SharePoint Date Bug",
        "ItemChildCount": "0",
        "FolderChildCount": "0",
        "_ComplianceFlags": "",
        "_ComplianceTag": "",
        "_ComplianceTagWrittenTime": "",
        "_ComplianceTagUserId": "",
        "AppAuthorLookupId": "24",
        "AppEditorLookupId": "24",
        "EventDate": "2020-01-01T00:00:00Z",
        "EndDate": "2020-01-12T23:59:00Z",
        "fAllDayEvent": true,
        "fRecurrence": false
}

Note that the response event date does not match the request previously sent.

Request = "EventDate": "2020-01-03T00:00:00Z"
Response = "EventDate": "2020-01-01T00:00:00Z"

Adding days before sending the request to SharePoint cannot be a viable long term solution.
A fix for this problem would be highly appreciated!