Database
[{"_id":1,generated:new Date("2020-01-01T00:00:00Z"),},{"_id":2,generated:new Date("2020-01-01T14:00:00Z"),}]
Query
db.collection.aggregate([{"$project":{"name":1,"generated":1,"timeSpend":{$divide:[{$subtract:[new Date("2020-01-01T17:00:00Z"),"$generated"]},3600000]}}},{"$match":{timeSpend:{$gt:14}}}])