[{"at":ISODate("2022-03-27T11:56:00.000Z"),"personIds":13355,"productIds":["c3cc8b62-f9f7-4845-8585-effb1efd790d","af59b890-61b6-45a6-b2a1-32e16ba1a136"]},{"at":ISODate("2022-03-28T11:56:00.000Z"),"personIds":13355,"productIds":["c3cc8b62-f9f7-4845-8585-effb1efd790d","af59b890-61b6-45a6-b2a1-32e16ba1a136","dg59b890-gdb6-4ere-asdd-23e16ba123a4"]},{"at":ISODate("2022-03-29T11:57:00.000Z"),"personIds":10347,"productIds":["920ba4e4-8d51-4e87-b40a-5d3f7b78d3ba"]}]

db.collection.aggregate([{"$match":{personIds:{"$in":[13355,10347]}}},{"$project":{at:{"$dateToParts":{"date":"$at"}},count:{"$size":"$productIds"},}},{"$match":{"at.day":{$gte:28,$lt:31},"at.hour":{$gte:10,$lte:22}}},{"$group":{"_id":null,"count":{"$max":"$count"}}},{"$project":{"_id":0}}])