#mongodb sort by date

mongodb sort bay date

   return Model.aggregate([
       { $lookup: {from: 'courses', localField: 'courseId', foreignField: '_id', as: 'course'} },
       { $sort: { date: 1 } },
       {$group : { _id: {
                   year : { $year: '$date' },
                   month : { $month: '$date'},
                   day : { $dayOfMonth: '$date'},
                   // date: '$date'
               },
               'count' : { $sum: 1 },
               sessions: {$push: '$$ROOT'}
       }},
       { '$unwind': '$_id' },
       { $sort: { '_id.month': 1, '_id.day': 1} },
    ]);