meteorhacks:aggregate to group mongo documents - mongodb

Question

This Meteor server code tries to count all the records which are 4 months and newer with property size:'4', color:'white' but account all entires from any one user as one count, so no mater how many documents have been entered by the same user, the are all counted as one. but I am getting nothing in return. any ideas? thx
let date = new Date();
date.setMonth(date.getMonth() - 4);
let doc = UsageCol.aggregate([{
$match: {
createdAt: {
$gte: date,
$lte: new Date()
},
action: 'failBroadcast',
plate: plate
}
}, {
$group: {
_id: {
userId: "$userId"
},
count: {
$sum: 1
}
}
}]);
for (var i = 0; i < doc.length; i++) {
var obj = doc[i];
console.log(JSON.stringify(obj));
}

Answer 1

Alright I just wanted to clear some things up from this morning.
The only reason I recommended moment js was thinking we are storing the date in date type and there is no easy way to dynamically create date in UTC using java script date function
So now that we know you used Date.now() to save the dates, you don't need any moment js.
The correct syntax is
let dateToMillis = Date.now(); //The current millis from epoch.
let dateFrom = new Date(dateToMillis); // Use the current millis from epoch.
let dateFromMillis = dateFrom.setMonth(dateFrom.getMonth() - 4); // The millis 4 months ago from epoch.
Pass dateToMillis and dateFromMillis to aggregation query.