title: how to convert incoming Json date into java date format?
body: <p>I am working on Xero accounts Apis 
  In json response i am getting date like below</p>
  
  <pre><code> "Date": "/Date(1455447600000+1300)/",
  </code></pre>
  
  <p>also same date in getting in dateString field like </p>
  
  <pre><code>"DateString": "2016-02-15T00:00:00",
  </code></pre>
  
  <p>i am trying to convert above date into string but getting different date. as in our api both dates are same, in Date field and DateString field.</p>
  
  <pre><code>Long longDate=Long.valueOf("1455447600000")+Long.valueOf("1300");
          Date date = new Date(longDate);
  
          //TimeZone timeZone = TimeZone.getTimeZone("UTC"); //also tried this
          Calendar cal=Calendar.getInstance();
          cal.setTime(date);
          System.out.println(cal.getTime());
  </code></pre>
  
  <p>output: <code>Sun Feb 14 16:30:01 IST 2016</code>   14 Feb but in StringDate it's <code>15 Feb</code></p>
  
  <p>json:</p>
  
  <pre><code>[
    {
      "Date": "/Date(1455447600000+1300)/",
      "Type": "ACCREC",
      "Total": 460,
      "Status": "AUTHORISED",
      "Contact": {
        "Name": "nn",
        "Phones": [
  
        ],
        "Addresses": [
  
        ],
        "ContactID": "6831fd62-d6f1-4dc7-9338-24566074ecf6",
        "ContactGroups": [
  
        ],
        "ContactPersons": [
  
        ],
        "HasValidationErrors": false
      },
      "DueDate": "/Date(1455620400000+1300)/",
      "Payments": [
  
      ],
      "SubTotal": 460,
      "TotalTax": 0,
      "AmountDue": 460,
      "HasErrors": false,
      "InvoiceID": "dcf1f09e-3e98-443e-981e-cdd9f296d607",
      "LineItems": [
        {
          "TaxType": "OUTPUT",
          "ItemCode": "Item2",
          "Quantity": 20,
          "Tracking": [
  
          ],
          "TaxAmount": 0,
          "LineAmount": 460,
          "LineItemID": "2a6c5078-a462-4e8c-b277-d1164885b7d9",
          "UnitAmount": 23,
          "AccountCode": "200",
          "Description": "Item2"
        }
      ],
      "Reference": "43223",
      "AmountPaid": 0,
      "DateString": "2016-02-15T00:00:00",
      "CreditNotes": [
  
      ],
      "Prepayments": [
  
      ],
      "CurrencyCode": "INR",
      "CurrencyRate": 1,
      "IsDiscounted": false,
      "Overpayments": [
  
      ],
      "DueDateString": "2016-02-17T00:00:00",
      "InvoiceNumber": "INV-0002",
      "AmountCredited": 0,
      "HasAttachments": false,
      "UpdatedDateUTC": "/Date(1455475695503+1300)/",
      "LineAmountTypes": "Exclusive"
    }
  ]
  </code></pre>