Firestore query by date range

Since I have the dueDate field stored as "timestamp" (and NOT as string or number) on Cloud Firestore, I did this to get the invoice documents with a due date on 2017:

let start = new Date('2017-01-01');
let end = new Date('2018-01-01');

this.afs.collection('invoices', ref => ref
  .where('dueDate', '>', start)
  .where('dueDate', '<', end)
);

NOTE: dueDate field was stored at firebase with a Date() object. e.g.: this.doc.dueDate = new Date('2017-12-25')

You could store the datetime object as Unix time (seconds since 1 January 1970). Then you can simple use the where select like this:

collectionRef.where("startTime", ">=", "1506816000").where("startTime", "<=", "1507593600")

Btw - to convert from datetime to Unix time in your app, you can use the excellent (now deprecated) library moment (if you are building something with js or node).

    var startfulldate = admin.firestore.Timestamp.fromDate(new Date(1556062581000));
    db.collection('mycollection')
      .where('start_time', '<=', startfulldate)
      .get()
      .then(snapshot => {              
            var jsonvalue: any[] = [];
            snapshot.forEach(docs => {
              jsonvalue.push(docs.data())
               })
                 res.send(jsonvalue);
                 return;
                }).catch( error => {
                    res.status(500).send(error)
                });

const event = new Date();
const expirationDate = admin.firestore.Timestamp.fromDate(event);
const query = collectionRef.where('startTime', '<=', expirationDate)