Java/MongoDB query by date

What you're doing is querying only with {$lte: toDate} losing $gte operator in the key overwrite. What you want is:

query.put("dateAdded", BasicDBObjectBuilder.start("$gte", fromDate).add("$lte", toDate).get());

If you are using MongoTemplate of Spring-Data Mongodb, you can do the same in following way:-

public List<Link> getLinksBetweenDate(Date startDate, Date endDate) {
            Query query = new Query().addCriteria(Criteria.where("updatedOn").gt(startDate).lte(endDate));
            return mongoTemplate.find(query, Link.class);
        }

Using mongo client 3.0

DateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ENGLISH);
Bson filter = new Document("$gte", format.parse("2015-05-01T00:00:00Z")).append("$lt", format.parse("2015-05-02T00:00:00Z"));
long count = db.getCollection("colection").count(new Document("field",filter) );