New/Update-MgUserEvent only updates Subject and ShowAs

Question

Here's a portion of the code to create a new calendar event:

Connect-MgGraph -TenantId $TenantId -ClientId $ClientId -CertificateThumbprint $Thumbprint
$User = Get-MgUser -UserId "******@contoso.com"
$startDateTime = @{
DateTime = "2025-04-15T14:00:00"
TimeZone = "Eastern Standard Time"
}
$endDateTime = @{
DateTime = "2025-04-15T15:00:00"
TimeZone = "Eastern Standard Time"
}
$NewEvent = @{
Start = $startDateTime
End = $endDateTime
Subject = "Sample Test Event"
}
$createEvent = New-MgUserEvent -UserId $User.Id -BodyParameter $NewEvent

This creates a new calendar event but not using the correct time; it creates a 30-minute event at the next 30-minute block (e.g., at 1:44, it will create a 2:00-2:30 event). Similarly, when I use Update-MgUserEvent, it only changes the subject regardless of any other properties I request to change. I tested updating most of the fields, and the only ones that would change were Subject and ShowAs (though I don't care about changing the value for ShowAs). Connect-MgGraph app permissions are Calendars.Read, Calendars.ReadBasic.All, Calendars.ReadWrite, and User.Read.All. No errors are reported; it just doesn't create or update anything except for the Subject (and ShowAs).

Answer 1

Hello Edwin J. Wensley,

I understand you are trying to create a calendar event using New-MgUserEvent, but the event is always created at the next 30-minute time block, and the time or time zone you provide is ignored.

This is a known issue in the Microsoft Graph PowerShell SDK and has been reported by other users as well.

You can track the issue on GitHub here:

https://github.com/microsoftgraph/msgraph-sdk-powershell/issues/3271

Until the fix is released, you can use Invoke-MgGraphRequest to create the event correctly. Here's how you can do it using the same input values from your original script:

$TenantId = "tenantId"

$ClientId = "appId"

$Thumbprint = "thumbprint"

Connect-MgGraph -TenantId $TenantId -ClientId $ClientId -CertificateThumbprint $Thumbprint

$UserId = "******@xxxxxxxxxxx.onmicrosoft.com"

$EventPayload = @{

    subject = "Sample Test Event"

    start = @{

        dateTime = "2025-04-17T14:00:00"

        timeZone = "Eastern Standard Time"

    }

    end = @{

        dateTime = "2025-04-17T15:00:00"

        timeZone = "Eastern Standard Time"

    }

} | ConvertTo-Json -Depth 10

Invoke-MgGraphRequest -Method POST `

    -Uri "https://graph.microsoft.com/v1.0/users/$UserId/events" `

    -Body $EventPayload `

    -ContentType "application/json

This will create the event at the correct time using the exact values you specify.

Hope this helps!

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