Mongoose saving and retrieving dates with UTC time, change to server timezone

I'm using mongoose models to save my records including created and updated dates. Here's my model schema:

var CasesModelSchema = new mongoose.Schema(
    {
        caseId: Number,
        sessionId: String,
        createdAt: {type: Date},
        updatedAt: {type: Date, default: Date.now},
        docs: mongoose.Schema.Types.Mixed
    },
    {
        collection: 'cases'
    }
);

The problem I'm facing is that the updatedAt field saves the datetime as ISODate("2017-04-24T12:40:48.193Z"), which is in UTC, but my server's timezone is Asia/Calcutta. Since I need to make queries according to my server's time, I need the datetimes to be saved in my preferred timezone.

Here's the query I need to execute (get all data for the last 10 days)

var today = moment(moment().format('YYYY-MM-DD')).toDate();
var tenDaysDate = moment(moment().format('YYYY-MM-DD')).add(-10, 'days').toDate();

CasesModel.findOne({updatedAt: {$gte: tenDaysDate, $lt: today}}, 
    function(err, caseData){
    cl(caseData, __line);
});

What I want is to do a query to get all the updated records in the last 10 days, exactly from 10 days ago midnight (Asia/Calcutta timezone) to today's midnight (Asia/Calcutta timezone). How do I do that?

via gaganshera