Database
[{"_id":ObjectId("665e1e9f2c8963573b18c261"),"timestamp":ISODate("2024-06-17T13:00:00.000Z")},{"_id":ObjectId("665e1e9f2c8963573b18c262"),"timestamp":ISODate("2024-06-17T20:00:00.000Z")}]
Query
db.collection.update({$expr:{$eq:[13,{"$hour":"$timestamp"}]}},[{"$set":{"timestamp":{"$dateAdd":{"startDate":"$timestamp","unit":"hour","amount":7}}}}],{multi:true})