Database
[{"reserved":[ISODate("2021-04-24T05:56:26.994Z"),ISODate("2021-04-25T05:56:26.994Z")]}]
Query
db.collection.update({},[{$set:{reserved:{$filter:{input:"$reserved",cond:{$not:{$in:["$$this",[ISODate("2021-04-24T05:56:26.994Z"),ISODate("2021-04-25T05:56:26.994Z")]]}}}}}},{$set:{reserved:{$concatArrays:["$reserved",[ISODate("2021-04-26T05:56:26.994Z"),ISODate("2021-04-27T05:56:26.994Z")]]}}}])