Issue with Mongoose Timestamp and epoch conversion to Date()

Question

I have a Mongoose schema with the timestamp option set as true.

schema = new mongoose.Schema({
    ...
},
{ timestamps: true });

Now I have an Android application that gets the timestamp using System.currentTimeMillis() which works all well and good and gives me number of milliseconds since UNIX epoch time.

I send this data across to my Node.js / Express server which takes the time and returns only documents created after that particular date.

// get all docs
router.get('/api/seekers', function(req, res) {
    Seeker.find({createdAt:{ $gt: new Date(req.query.timestamp) }}, function(err, seekers) {
        if(err)
            res.send(err);
        else 
            res.json(seekers);
    });
});

So I send https://api_url.com/api/seekers?timestamp=1479431351762 as a request to the server.

Now a couple of things happen:

1. I send the value in milliseconds and get this error

   {"message":"Cast to date failed for value \\"Invalid Date\\" at path \\"updatedAt\\"","name":"CastError","kind":"date","value":null,"path":"updatedAt"}

   After a little bit of investigation, it turns out you need to pass seconds to Date() . So,

2. I divide the value by 1000 to get seconds ( req.query.timestamp/1000 ). Now I wasn't getting an error, but the query constraint was not working. I'm getting all values since the beginning of time.

3. I moved over to the Mongo shell to check whether the issue persists, to which it turns out it doesn't since I can pass the millisecond value to Mongo's Date:

   > new Date(1479431351762) ISODate("2016-11-18T01:09:11.762Z")

   But if I tried passing the second value to Date() , it turns out it actually was sending me to the beginning of time:

   > new Date(1479431351) ISODate("1970-01-18T02:57:11.351Z")

I'm unable to figure this out, what can I do so server request and mongoose correctly processes the timestamp and queries my db?

Answer 1

Any wanderers with the same issue, who might have missed chridam 's comment, you just need to cast the passed timestamp to int before parsing. This works:

new Date(parseInt(req.query.timestamp))