REST endpoint to pull LeadActivities

Hi, I want to pull lead activities periodically. I have a scheduled job that does the work.

Below is one of the lead activity in Marketo.

I am getting this lead activity when I acquires a page token with below URLs.

<>.mktorest.com/rest/v1/activities/pagingtoken.json?access_token=<>&sinceDatetime=2015-10-23 10:00:00Z

and

<>.mktorest.com/rest/v1/activities/pagingtoken.json?access_token=<>&sinceDatetime=2015-10-23 10:02:00Z

Can some one explain why I am getting this activity with second page token as its datetime is greater then the datetime when activity was created?

Why is activityDate and date inside attributes different?

Time zone of the user who reated this activity is IST, timezone of api user is PDT.

Activity

____________________________________________________

{

  "requestId": "13442#150a031a1e2",

  "result": [

    {

      "id": 911881,

      "leadId": 157210,

      "activityDate": "2015-10-23T10:00:20Z",

      "activityTypeId": 46,

      "primaryAttributeValue": "Milestone",

      "attributes": [

        {

          "name": "Date",

          "value": "2015-10-23 05:00:20"

        },

        {

          "name": "Description",

          "value": "IM Milestone"

        },

        {

          "name": "Source",

          "value": "Lead action"

        }

      ]

    }

  ],

  "success": true,

  "nextPageToken": "44FLW5KAAOOYT5OI7XY5XJIS6G54FZWS52MTWFJCRMSM3EBIGQLA====",

  "moreResult": true

}