q.json

[
{"$match": {
     "date": {
         "$gte":"2016-03-11 18:00:00", 
         "$lte":"2016-04-11 18:00:00"
     },
     "userID": 102}
},
{ "$project" : {"fDate":{"$add": ["$date", 21600000]}, "stats":1, "date": 1, "userID": 1}},
{
"$group": { 
    "_id": { "year": { "$year": "$fDate" }, "dayOfYear": { "$dayOfYear": "$fDate" }, "userID": "$userID" }, 
    "userID" : { "$last": "$userID" },
    "lastUpdate" : { "$last": "$date" },
    "countOrder": {"$sum": "$stats.countOrder"},
    "priceTotal": {"$sum": "$stats.priceTotal"},
    "priceLostProfit": {"$sum": "$stats.priceLostProfit"},
    "countCanceled": {"$sum": "$stats.countCanceled"},
    "countCompleted": {"$sum": "$stats.countCompleted"}
}
}, 
{ "$project" : { 
    "_id": 0, 
    "userID": "$userID",
    "lastUpdate": "$lastUpdate",
    "stats": { 
        "countOrder": "$countOrder", 
        "priceTotal": "$priceTotal",
        "priceLostProfit": "$priceLostProfit",
        "countCanceled": "$countCanceled",
        "countCompleted":"$countCompleted"
    }} },
    { "$sort": { "lastUpdate" : 1 } }
]