[{_id:"e82d0b5c-5e38-4442-a678-f29245681238",start_time:"2020-02-25T20:45:10.623Z",stop_time:"2020-02-26T21:45:10.623Z",data:{cost:3,buyer:"John"}},{_id:"2",start_time:"2020-02-25T20:45:10.623Z",stop_time:"2020-02-25T21:45:10.623Z",data:{cost:3,buyer:"John"}}]

db.collection.aggregate([{"$addFields":{"date_diff":{"$subtract":[{"$dateFromString":{"dateString":"$stop_time"}},{"$dateFromString":{"dateString":"$start_time"}}]}}},{"$match":{"date_diff":{"$gte":86400000}}}])