event: delta

Article
09/27/2023

Namespace: microsoft.graph

Important

APIs under the /beta version in Microsoft Graph are subject to change. Use of these APIs in production applications is not supported. To determine whether an API is available in v1.0, use the Version selector.

Get a set of event resources that have been added, deleted, or updated in one or more calendars.

You can get specific types of these incremental changes in the events in all the calendars of a mailbox or in a specific calendar, or in an event collection of a calendarView (range of events defined by start and end dates) of a calendar. The calendar can be the default calendar or some other specified calendar of the user's. In the case of getting incremental changes on calendarView, the calendar can be a group calendar as well.

Typically, synchronizing events in a calendar or calendarView in a local store entails a round of multiple delta function calls. The initial call is a full synchronization, and every subsequent delta call in the same round gets the incremental changes (additions, deletions, or updates). This allows you to maintain and synchronize a local store of events in the specified calendar, without having to fetch all the events of that calendar from the server every time.

The following table lists the differences between the delta function on events and the delta function on a calendarView in a calendar.

Delta function on events	Delta function on calendarView
Gets incremental changes of all the events in a calendar not bounded by a start and end date range. Alternatively, you can get incremental changes of the events in a calendar bounded by a start time, starting on or after that date/time.	Gets incremental changes of events within the start and end date/time of the calendarView.
Returns only a limited set of event properties for performance reasons. Client to subsequently use `GET /events/{id}` to expand any events.	Server-side expansion returns a fuller set of event properties.
Response includes single instances and recurring series master.	Response includes single instances, and occurrences and exceptions of recurring series.
Applies to events in user calendars but not group calendars.	Applies to events in user and group calendars.
Currently available only in the beta version.	Available in the v1.0 and beta versions.

This API is available in the following national cloud deployments.

Global service	US Government L4	US Government L5 (DOD)	China operated by 21Vianet
✅	✅	✅	✅

Permissions

Choose the permission or permissions marked as least privileged for this API. Use a higher privileged permission or permissions only if your app requires it. For details about delegated and application permissions, see Permission types. To learn more about these permissions, see the permissions reference.

Permission type	Least privileged permissions	Higher privileged permissions
Delegated (work or school account)	Calendars.ReadBasic	Calendars.Read, Calendars.ReadWrite
Delegated (personal Microsoft account)	Calendars.ReadBasic	Calendars.Read, Calendars.ReadWrite
Application	Calendars.Read	Calendars.ReadBasic, Calendars.ReadWrite

HTTP request

This section shows the HTTP request syntax for the initial delta function call to start a full synchronization that retrieves all the events in the specified calendar or calendar view. This syntax does not contain any state tokens.

The query URL returned in a @odata.nextLink or @odata.deltaLink of a successful response includes a state token. For any subsequent delta function call, use the query URL in a @odata.nextLink or @odata.deltaLink preceding it.

Delta function on events in a user calendar (preview)

Apply the delta function on all the events or events starting on or after a specific date/time, in the specified user calendar(s):

To get incremental changes of all the events, or of events starting on or after the specified date/time in the user's mailbox:

GET /me/events/delta
GET /users/{id | userPrincipalName}/events/delta

GET /me/events/delta?startDateTime={start_datetime}
GET /users/{id | userPrincipalName}/events/delta?startDateTime={start_datetime}

To get incremental changes of all the events, or of events starting on or after the specified date/time in the user's default calendar:

GET /me/calendar/events/delta
GET /users/{id | userPrincipalName}/calendar/events/delta

GET /me/calendar/events/delta?startDateTime={start_datetime}
GET /users/{id | userPrincipalName}/calendar/events/delta?startDateTime={start_datetime}

To get incremental changes of all the events, or of events starting on or after the specified date/time in the specified user calendar:

GET /me/calendars/{id}/events/delta
GET /users/{id | userPrincipalName}/calendars/{id}/events/delta

GET /me/calendars/{id}/events/delta?startDateTime={start_datetime}
GET /users/{id | userPrincipalName}/calendars/{id}/events/delta?startDateTime={start_datetime}

To get incremental changes all the events, or of events starting on or after the specified date/time in the specified calendar group and calendar:

GET /me/calendarGroups/{id}/calendars/{id}/events/delta
GET /users/{id | userPrincipalName}/calendarGroups/{id}/calendars/{id}/events/delta

GET /me/calendarGroups/{id}/calendars/{id}/events/delta?startDateTime={start_datetime}
GET /users/{id | userPrincipalName}/calendarGroups/{id}/calendars/{id}/events/delta?startDateTime={start_datetime}

Delta function on calendarView in a user calendar

Apply the delta function on a range of events delimited by start and end date/times, in the specified user calendar:

To get incremental changes in a calendar view of the user's default calendar:

GET /me/calendarView/delta?startDateTime={start_datetime}&endDateTime={end_datetime}
GET /users/{id}/calendarView/delta?startDateTime={start_datetime}&endDateTime={end_datetime}

To get incremental changes in a calendar view of the specified user calendar:

GET /me/calendars/{id}/calendarView/delta?startDateTime={start_datetime}&endDateTime={end_datetime}
GET /users/{id}/calendars/{id}/calendarView/delta?startDateTime={start_datetime}&endDateTime={end_datetime}

Delta function on calendarView in a group calendar

To get incremental changes in a calendar view of a group's calendar:

GET /groups/{id}/calendarView?startDateTime={start_datetime}&endDateTime={end_datetime}

Query parameters

Tracking changes incurs a round of one or more delta function calls. If you use any query parameter (other than $deltatoken and $skiptoken), you must specify it in the initial delta request. Microsoft Graph automatically encodes any specified parameters into the token portion of the @odata.nextLink or @odata.deltaLink URL provided in the response. You only need to specify any desired query parameters once upfront. In subsequent requests, simply copy and apply the @odata.nextLink or @odata.deltaLink URL from the previous response, as that URL already includes the encoded, desired parameters.

Query parameter	Type	Description
startDateTime	String	The start date and time of the time range, represented in ISO 8601 format. For example, "2019-11-08T19:00:00-08:00". The timezone is specified in the timezone offset portion of the parameter value, and is not impacted by the `Prefer: outlook.timezone` header if present. If no timezone offset is included in the value, it is interpreted as UTC. Optional for delta on events in a calendar. Required for delta on calendarView.
endDateTime	String	The end date and time of the time range, represented in ISO 8601 format. For example, "2019-11-08T20:00:00-08:00". The timezone is specified in the timezone offset portion of the parameter value, and is not impacted by the `Prefer: outlook.timezone` header if present. If no timezone offset is included in the value, it is interpreted as UTC. Not supported by delta on events in a calendar. Required for delta on calendarView.
$deltatoken	string	A state token returned in the `@odata.deltaLink` URL of the previous delta function call for the same calendar view, indicating the completion of that round of change tracking. Save and apply the entire `@odata.deltaLink` URL including this token in the first request of the next round of change tracking for that calendar view.
$skiptoken	string	A state token returned in the `@odata.nextLink` URL of the previous delta function call, indicating there are further changes to be tracked in the same calendar view.

OData query parameters

Expect a delta function call on a calendarView to return the same properties you'd normally get from a GET /calendarView request. You cannot use $select to get only a subset of those properties.
The delta function doesn't support the following query parameters for events in a user calendar, or events in a calendarView: $expand, $filter,$orderby, $search, and $select.

Request headers

Name	Type	Description
Authorization	string	Bearer {token}. Required. Learn more about authentication and authorization.
Content-Type	string	application/json. Required.
Prefer	string	odata.maxpagesize={x}. Optional.
Prefer	string	outlook.timezone={Time zone string}. Optional, UTC assumed if absent.

Response

Delta function on events (preview)

If successful, this method returns a 200 OK response code and an event collection in the response body. Each event in the response contains only the id, type, start and end properties for performance reasons. Use GET /events/{id} subsequently to expand any events from the response.

Delta function on calendarView

If successful, this method returns a 200 OK response code and an event collection in the response body.

Expect to get all the properties you'd normally get from a GET /calendarView request.

Within a round of delta function calls bound by the date range of a calendarView, you may find a delta call returning two types of events under @removed with the reason deleted:

Events that are within the date range and that have been deleted since the previous delta call.
Events that are outside the date range and that have been added, deleted, or updated since the the previous delta call.

Filter the events under @removed for the date range that your scenario requires.

Examples

Example 1: Delta function on events in a calendar (preview)

Request

The following example shows the initial sync request to get events in the signed-in user's default calendar, that occur on or after the specified startDateTime parameter. The initial request does not include any state token.

The request uses the Prefer: odata.maxpagesize header to limit the maximum number of events in each response to 1. Continue calling the delta function by using the query returned in @odata.nextLink until you get a @odata.deltaLink in the response.

GET https://graph.microsoft.com/beta/me/calendar/events/delta?startDateTime=2020-06-12T00:00:00Z

Prefer: odata.maxpagesize=1



mgc-beta users calendar events delta get --user-id {user-id} --start-date-time "2020-06-12T00:00:00Z"

Important

Microsoft Graph SDKs use the v1.0 version of the API by default, and do not support all the types, properties, and APIs available in the beta version. For details about accessing the beta API with the SDK, see Use the Microsoft Graph SDKs with the beta API.

For details about how to add the SDK to your project and create an authProvider instance, see the SDK documentation.


const options = {
	authProvider,
};

const client = Client.init(options);

let delta = await client.api('/me/calendar/events/delta?startDateTime=2020-06-12T00:00:00Z')
	.version('beta')
	.get();

Important

For details about how to add the SDK to your project and create an authProvider instance, see the SDK documentation.

Response

If the request is successful, the response includes a state token, which is either a skipToken (in an @odata.nextLink response header) or a deltaToken (in an @odata.deltaLink response header). Respectively, they indicate whether you should continue with the round or you have completed getting all the changes for that round.

The response below shows a skipToken in an @odata.nextLink response header.

HTTP/1.1 200 OK
Content-type: application/json

{
  "@odata.nextLink":"https://graph.microsoft.com/beta/me/calendar/events/delta?$skiptoken=R0usmcdvmMu7jxWP8",
  "value": [
    {
      "id": " AAMkADllMWMwNDkzLWJlY2EtNDIyOS1iZjAA=",
      "type": "singleInstance",
      "start": {
             "DateTime": "2020-02-19T10:00:00.0000000", 
             "TimeZone": "UTC"
         }, 
       "end": {
                "DateTime": "2020-02-19T11:00:00.0000000", 
                "TimeZone": "UTC"      
          } 
        }
  ]
}

Example 2: Delta function on calendarView

Request

The following example shows the initial sync request to get events in the specified calendar of the signed-in user, within the range of dates indicated by the calendarView. The initial request does not include any state token.

The request uses the Prefer: odata.maxpagesize header to limit the maximum number of events in each response to 2. Continue calling the delta function by using the query returned in @odata.nextLink until you get all the events in that calendar view, and a @odata.deltaLink in the response.

GET https://graph.microsoft.com/beta/me/calendars/AAMkADI5M1BbeAAA=/calendarView/delta?startDateTime=2020-06-01T00:00:00Z&endDateTime=2020-06-10T00:00:00Z

Prefer: odata.maxpagesize=2



mgc-beta users calendars calendar-view delta get --user-id {user-id} --calendar-id {calendar-id} --start-date-time "2020-06-01T00:00:00Z" --end-date-time "2020-06-10T00:00:00Z"

Important

For details about how to add the SDK to your project and create an authProvider instance, see the SDK documentation.


const options = {
	authProvider,
};

const client = Client.init(options);

let delta = await client.api('/me/calendars/AAMkADI5M1BbeAAA=/calendarView/delta?startDateTime=2020-06-01T00:00:00Z&endDateTime=2020-06-10T00:00:00Z')
	.version('beta')
	.get();

Important

For details about how to add the SDK to your project and create an authProvider instance, see the SDK documentation.

Response

The response below shows a skipToken in an @odata.nextLink response header.

Note: The response object shown here might be shortened for readability.

HTTP/1.1 200 OK
Content-type: application/json

{
    "@odata.context": "https://graph.microsoft.com/beta/$metadata#Collection(event)",
    "@odata.nextLink": "https://graph.microsoft.com/beta/me/calendars/AAMkADI5M1BbeAAA=/calendarView/delta?$skiptoken=R0usmcdvmMu7jxWP8",
    "value": [
        {
            "@odata.type": "#microsoft.graph.event",
            "@odata.etag": "W/\"Jdsb3FEkPk2qoUHCdliYowACwixTgw==\"",
            "createdDateTime": "2020-06-16T04:05:43.8668791Z",
            "lastModifiedDateTime": "2020-06-16T04:08:27.354268Z",
            "changeKey": "Jdsb3FEkPk2qoUHCdliYowACwixTgw==",
            "categories": [],
            "transactionId": null,
            "originalStartTimeZone": "Pacific Standard Time",
            "originalEndTimeZone": "Pacific Standard Time",
            "uid": "040000008200E00074C5B7101A82E00800000000F088B8B95843D601000000000000000010000000165CD5547CFC9545B6492B261750B48C",
            "reminderMinutesBeforeStart": 15,
            "isReminderOn": false,
            "hasAttachments": false,
            "subject": "Summer party",
            "bodyPreview": "",
            "importance": "normal",
            "sensitivity": "normal",
            "isAllDay": false,
            "isCancelled": false,
            "isOrganizer": true,
            "IsRoomRequested": false,
            "AutoRoomBookingStatus": "None",
            "responseRequested": true,
            "seriesMasterId": null,
            "showAs": "busy",
            "type": "singleInstance",
            "webLink": "https://outlook.office365.com/owa/?itemid=AAMkADI5MAAKkeE1QAAA%3D&exvsurl=1&path=/calendar/item",
            "onlineMeetingUrl": null,
            "isOnlineMeeting": false,
            "onlineMeetingProvider": "unknown",
            "allowNewTimeProposals": true,
            "OccurrenceId": null,
            "isDraft": false,
            "recurrence": null,
            "AutoRoomBookingOptions": null,
            "onlineMeeting": null,
            "id": "AAMkADI5MAAKkeE1QAAA=",
            "responseStatus": {
                "response": "none",
                "time": "0001-01-01T00:00:00Z"
            },
            "body": {
                "contentType": "html",
                "content": "<html>\r\n<head></head>\r\n<body lang=\"EN-US\" link=\"#0563C1\" vlink=\"#954F72\" style=\"\">\r\n<div class=\"WordSection1\">\r\n<p class=\"MsoNormal\">&nbsp;</p>\r\n</div>\r\n</body>\r\n</html>\r\n"
            },
            "start": {
                "dateTime": "2020-06-02T20:00:00.0000000",
                "timeZone": "UTC"
            },
            "end": {
                "dateTime": "2020-06-02T22:30:00.0000000",
                "timeZone": "UTC"
            },
            "location": {
                "displayName": "",
                "locationType": "default",
                "uniqueIdType": "unknown",
                "address": {
                    "type": "unknown"
                },
                "coordinates": {}
            },
            "locations": [],
            "attendees": [
                {
                    "type": "required",
                    "status": {
                        "response": "none",
                        "time": "0001-01-01T00:00:00Z"
                    },
                    "emailAddress": {
                        "name": "Samantha Booth",
                        "address": "samanthab@contoso.com"
                    }
                }
            ],
            "organizer": {
                "emailAddress": {
                    "name": "Samantha Booth",
                    "address": "samanthab@contoso.com"
                }
            }
        },
        {
            "@odata.type": "#microsoft.graph.event",
            "@odata.etag": "W/\"Jdsb3FEkPk2qoUHCdliYowACwixTfw==\"",
            "createdDateTime": "2020-06-16T04:06:18.386713Z",
            "lastModifiedDateTime": "2020-06-16T04:08:19.5694048Z",
            "changeKey": "Jdsb3FEkPk2qoUHCdliYowACwixTfw==",
            "categories": [],
            "transactionId": null,
            "originalStartTimeZone": "Pacific Standard Time",
            "originalEndTimeZone": "Pacific Standard Time",
            "uid": "040000008200E00074C5B7101A82E0080000000060074BC55843D6010000000000000000100000002D33A89F36B10D43A12FD990B62858B2",
            "reminderMinutesBeforeStart": 15,
            "isReminderOn": true,
            "hasAttachments": false,
            "subject": "Summer party part 2",
            "bodyPreview": "",
            "importance": "normal",
            "sensitivity": "normal",
            "isAllDay": false,
            "isCancelled": false,
            "isOrganizer": true,
            "IsRoomRequested": false,
            "AutoRoomBookingStatus": "None",
            "responseRequested": true,
            "seriesMasterId": null,
            "showAs": "busy",
            "type": "singleInstance",
            "webLink": "https://outlook.office365.com/owa/?itemid=AAMkADI5MAAKkeE1RAAA%3D&exvsurl=1&path=/calendar/item",
            "onlineMeetingUrl": null,
            "isOnlineMeeting": false,
            "onlineMeetingProvider": "unknown",
            "allowNewTimeProposals": true,
            "OccurrenceId": null,
            "isDraft": false,
            "recurrence": null,
            "AutoRoomBookingOptions": null,
            "onlineMeeting": null,
            "id": "AAMkADI5MAAKkeE1RAAA=",
            "responseStatus": {
                "response": "none",
                "time": "0001-01-01T00:00:00Z"
            },
            "body": {
                "contentType": "html",
                "content": "<html>\r\n<head></head>\r\n<body lang=\"EN-US\" link=\"#0563C1\" vlink=\"#954F72\" style=\"\">\r\n<div class=\"WordSection1\">\r\n<p class=\"MsoNormal\">&nbsp;</p>\r\n</div>\r\n</body>\r\n</html>\r\n"
            },
            "start": {
                "dateTime": "2020-06-04T19:30:00.0000000",
                "timeZone": "UTC"
            },
            "end": {
                "dateTime": "2020-06-04T22:30:00.0000000",
                "timeZone": "UTC"
            },
            "location": {
                "displayName": "",
                "locationType": "default",
                "uniqueIdType": "unknown",
                "address": {
                    "type": "unknown"
                },
                "coordinates": {}
            },
            "locations": [],
            "attendees": [
                {
                    "type": "required",
                    "status": {
                        "response": "none",
                        "time": "0001-01-01T00:00:00Z"
                    },
                    "emailAddress": {
                        "name": "Samantha Booth",
                        "address": "samanthab@contoso.com"
                    }
                }
            ],
            "organizer": {
                "emailAddress": {
                    "name": "Samantha Booth",
                    "address": "samanthab@contoso.com"
                }
            }
        }
    ]
}

Share via

event: delta

Permissions

HTTP request

Delta function on events in a user calendar (preview)

Delta function on calendarView in a user calendar

Delta function on calendarView in a group calendar

Query parameters

OData query parameters

Request headers

Response

Delta function on events (preview)

Delta function on calendarView

Examples

Example 1: Delta function on events in a calendar (preview)

Request

Response

Example 2: Delta function on calendarView

Request

Response

Feedback

Additional resources

Share via

event: delta

Permissions

HTTP request

Delta function on events in a user calendar (preview)

Delta function on calendarView in a user calendar

Delta function on calendarView in a group calendar

Query parameters

OData query parameters

Request headers

Response

Delta function on events (preview)

Delta function on calendarView

Examples

Example 1: Delta function on events in a calendar (preview)

Request

Response

Example 2: Delta function on calendarView

Request

Response

Related content

Feedback

Additional resources