Database
[{"key":1,start_local_datetime:ISODate("2019-08-23T10:17:42.000+00:00"),terminate_local_datetime:ISODate("2019-09-19T10:17:42.000+00:00")},{"key":2,start_local_datetime:ISODate("2019-08-23T10:17:42.000+00:00"),terminate_local_datetime:ISODate("2019-08-25T10:17:42.000+00:00")}]
Query
db.collection.aggregate([{"$addFields":{"timeDifference":{"$divide":[{"$subtract":["$terminate_local_datetime","$start_local_datetime"]},86400000]}}},{"$match":{$expr:{"$gt":["$timeDifference",10]}}},{"$project":{timeDifference:0}}])